My big brother and I were standing at the door to the showroom at Fort Worth Gold and Silver Exchange, the largest, busiest and most successful jewellery store in Texas.

“I can’t do it, Darren. I can’t face them.”

“It’s just talking to them. It’s not that hard, bud,” said Darren.

It was late November 1982 and Christmas music was playing. I was 15 years old, newly dropped out of high school and learning to be a jewellery salesman.

“I’m telling you I’m too nervous,” I replied. I’d suffered from acute shyness since early childhood.

“Well you’re just going to have to pretend,” said Darren.

The store had started me selling on the phones because it was easier to feign being older and more experienced. But it was almost Thanksgiving and they needed more bodies on the floor. Darren took me by the arm and we slipped behind the long row of twenty-something salespeople working the brass-and-glass counters. We called a number and my first real customer pushed her way through the crowd to the front.

I still remember that woman. She bought twister beads, a pair of very small diamond studs on promotion, and a gold bracelet. I was shaking as I showed her the goods, shaking as I took her money and still shaking as I called the next customer. But by the end of the day I could look a shopper in the eye and say, “I’m Clancy. What can I show you?”

That first Christmas season I didn’t believe I was a real jewellery salesman. I was performing. But every day I’d prepare by reciting stock sales lines to myself: “And what else can I show you?” or “Who else is on your Christmas list?” I’d talk with the other members of staff about sales I’d made the day before, or my targets for that week, or my plan to sell a Rolex. All of this helped me persuade myself that I could go in front of customers and pretend to know what I was doing.

To them I must have seemed barely a teenager, pimply in an oversized suit and a cheap Tabasco tie. Trembling and pretending to know what I was talking about, I acted as though I sold thousands of dollars of jewellery every day.

But after a week or two, I was doing exactly that. I remember the first Rolex I ever sold: a men’s President. The customer asked me if I was allowed to sell the watch. I lied and said this was my third Rolex that day. By the time he’d handed over his credit card, he told me that he had a car dealership, and if I ever wanted to make real money, I could come and work for him.

Every time I wrote up another sale and saw my name near the top of the day’s sales boards, I believed a little more that I actually was the salesman I was pretending to be. But, though the evidence was clear that I really could do this job, I still felt as though I was cheating, perpetually on the brink of being found out.

The feeling of being a fraud isn’t new, nor is our preoccupation with it. “All the world’s a stage...And one man in his time plays many parts,” wrote William Shakespeare. The principle of “fake it till you make it” has long propelled incompetents to greatness. The success of phoneys is endlessly fascinating. In the 2000s “On Bullshit”, a book by Harry Frankfurt, a Princeton philosopher, spent many weeks at the top of the New York Times’ bestseller list.

But recently we have become fixated on a particular aspect of fraudulence – impostor syndrome – the sense that we are always posturing, that our accomplishments are in some way undeserved, no matter how consistent the evidence to the contrary.

Impostor syndrome seems to have become an epidemic. That is partly because we have given the phenomenon a name. Two psychologists, Pauline Clance and Suzanne Imes, are credited with coining the term in a landmark study in the late 1970s, in which they identified the “internal experience” of feeling like an “intellectual phoney”. But our growing preoccupation with impostorism is also a result of profound social change.

In the past most people were employed to make things – and it’s fairly easy to distinguish an expert chairmaker or bricklayer from a novice. Many more of us now work in the service economy: our lives are spent creating impressions rather than tangible items. There is no objective standard for providing a “great customer experience”. To be an excellent manager is a nebulous thing. At every level of every field, the number of roles where achievement is neither entirely measurable nor objective has grown.

Professional life today leaves us straining to redefine ourselves. We no longer have “a job for life”, but instead search endlessly for promotion and variety, which leads us to promise things we don’t yet know how to do. “Pitch culture” has created an environment in which each of us is almost required to be an impostor in order to succeed.

The breakdown of class structures has exacerbated this phenomenon. The demise of the feudal system is a good thing, but when we are no longer born into a role, or when we find ourselves in a job that would have been unfamiliar to, or even impossible, for our parents, it’s hardly surprising that we worry about whether or not we deserve it.

These social factors also help to explain why the authors of that first academic paper on impostor syndrome immediately identified its greater prevalence and intensity among women rather than men (a finding that later studies have supported). They suggested that both early family dynamics and “societal sex-role stereotyping” meant that many highly successful women they interviewed attributed their achievements to luck, mistaken identity or faulty judgment on the part of their superiors. These same social expectations also probably contribute to the frequent feelings of being an impostor that many people from ethnic minorities also report.

For many of us, technological change has increased our sense of being an impostor, particularly in our private lives. We can constantly compare our experiences to those of others online. We can also hide behind our online selves, creating an outward persona that we know to be untrue. Though no doctor would recognise impostor syndrome as a genuine medical condition, ever more of us seem to experience it, either in our private or professional lives.

When you’re an impostor you expect to be exposed at any moment. It’s frightening. It is a bit like having an affair, I later discovered, or carrying any kind of secret shame: it seems as though everyone must know what you’re hiding.

The paradox of being an impostor as a salesman was that, in order to be able to sell jewellery, I had to (almost) convince myself that I could do it. That in turn allowed me to (almost) convince someone else I could do it. Once they believed in me, I, in turn, (almost) believed in myself. My confidence depended on their confidence, which depended on my initial fabrication of confidence. The whole Jenga tower of self-deception was wobbly and ready to collapse as soon as any piece was removed.

Eventually I became comfortable with the customers who knew no more about jewellery than I did. But take a brash man trying to push me around, or a high-roller asking to view a $20,000 ring in the diamond room, and I’d become so nervous I couldn’t remember what to say. Sometimes a more experienced salesperson would see what was happening and swoop in to save me. A few times customers demanded to speak with another, “real” salesperson: suddenly my imposture had been revealed.

Years later, when I had my own jewellery store, I’d tell new sales staff: “The customer wants to believe in you. You just have to have that confidence. That’s what you’re really selling.” I learned over the years that to be a great salesman was mostly to believe that you are a great salesman. I grew comfortable with the idea that my expertise in seeming to be a salesman was a function of my fitness for the job.

But I still doubted that I was really cut out to sell. On bad days it was hard to overcome the anxiety that everything was a pretence, and that, at any moment, someone might appear and see me for the fraud I knew myself to be.

The very ubiquity of feeling like an impostor should make the sentiment less frightening. A friend of mine, herself a high achiever, recently remarked only half in jest that she doesn’t trust anyone who doesn’t sometimes experience impostorism. It’s a valid point: we want successful people to have both enough self-awareness and enough self-doubt to question what they are doing and why. This way of thinking is a measure of humility.

But the fact remains that, just like me with my sweaty palms on the floor of the jewellery store, many of us come to a moment where we wonder how, when and where we will be unmasked.

The strange thing is that the more expert you become in a field, the stronger your feeling of impostorism. As a younger academic, I was less aware both of my own imperfections and my strategies for disguising them. But the older I get, the harder it is to believe my own bullshit. Becoming an expert has actually made me even more prone to impostor syndrome. People really think I know something now. Sometimes the expectation of others feels overwhelming.

I’ve been a philosophy professor for 17 years. I stand up and lecture impressionable young adults about the meaning of life – or, at least, how to think about and question the life each of us leads. It’s a discipline that’s founded on the importance of recognising and admitting one’s own ignorance (it was Socrates who said, “the only thing I know is that I know nothing”). Yet some people reckon this entire academic field is moonshine – I suspect that some of my students feel this way. These days most people treat me as though I know what I’m doing. But it’s a tough act, and I still worry that I’ll suddenly be exposed.

As a jewellery salesman I knew I was a con artist, and was pretty sure that most of my customers knew it too. I didn’t want to do it. But when I finally decided to study philosophy, for a brief period I loved it so much that I really thought I knew what I was talking about.

Denise Shull is a performance coach to elite athletes and high-flying business types. Wendy, the superstar psychiatrist in the American television drama “Billions”, is based on her. In the show, Wendy utters the line, “If you’re successful enough, people think you can do anything, and then you start to believe it, too.” But in real life, Shull is more interested in those who fail to convince themselves of their own worth.

When I asked her about impostor syndrome, she brought up a client of hers who is a big player in the hedge-fund world. “He opens his own hedge fund, and suddenly he thinks he’s made a mistake,” she says. “He can’t manage all these people. He even makes some bad trades. And this guy is a superstar. My job is to figure out where his confidence has gone.” Once Shull got to work, she realised that many of the components of her client’s new role – managing people, setting performance goals, worrying about paying the bills – were tasks he didn’t really enjoy. “So he’s convinced himself he can’t do something in a new role because he doesn’t want to do it.”

This is just one manifestation of impostor syndrome: when a person struggles to adapt to new challenges they often feel that the success they’ve enjoyed so far doesn’t represent who they really are. But for many of us it runs far deeper: a person who has proved their excellence time and again may still feel that they are somehow not up to the task, or are simply fooling those around them.

Recent research suggests that there are different types of impostor, each of which I have found myself experiencing at some point. The Anxious Impostor has negative views of themself that are unjustified by the best evidence. This is the most commonly identified and studied form of impostorism: the Anxious Impostor is particularly afflicted with doubt, stress and sometimes depression. As a young jewellery salesman, and even when I owned a chain of jewellery stores, I was the Anxious Impostor, believing that I was only fooling my customers that I could do the job, no matter how good I got at selling.

Next there is the Hustling Impostor, who engages in a more deliberate form of self-presentation to achieve ends that may otherwise be out of reach. When I became a college professor, I became more of a hustler. I knew I had to play the role of the learned elder in order to teach my students and gain the respect of my colleagues. Research suggests that the hustler probably feels better about themself than the Anxious Impostor. “Fake it till you make it” is not everybody’s story, but it is the way a lot of us begin our professional lives. As Nietzsche argued: “The profession of every man begins as a kind of hypocrisy, as a copying from without.”

There is also the Lazy Impostor – Shull’s client sounds like one of these – who tells themself that they aren’t up to the task because they don’t really want to do it.

Then there is the Modest Impostor, who sincerely doubts that he or she is as important as others claim, but does so in part because they don’t want to be seen as considering themself superior to others. As I’ve grown older I find myself more and more the Modest Impostor, even with my students. “Am I such an expert?” I ask them. “I don’t know. What do you think about the question?” It’s a self-protective strategy I can safely engage in because my authority as an expert is relatively well established, at least in my own small part of the academic world. This type of impostor can also carry great power: admit once in a job interview that you don’t know the answer to something, and that can give the helpful impression that your blithe answers to the other questions are genuinely well-founded.

Finally there is the Wise Impostor who acknowledges that most people, maybe all of us, have to fake it a little bit. When a bunch of professors get together, we tend to be Wise Impostors, admitting at least between ourselves that we have to bluff a bit to maintain our authority in the classroom and to get students to lower their guard.

The fear of being exposed as an impostor is crucial to the pain of impostorism. But the Wise Impostor knows this, so may expose themself first, both to avoid the problem and also to say: “But look! I’m more authentic than most, because at least I can admit my impostorism.” Perhaps the goal for all of us who suffer from impostorism is not so much to escape it as to graduate to the stance of the Wise Impostor.

You might say that I feel like a phoney all the time, and have done so for most of my adult life. That can be uncomfortable. We tend to think that the more sincerely we know ourselves, the more accurately we reveal our true selves to others and the better we are, therefore, as people.

The opposite view of oneself is an extreme one, represented at the moment most notoriously by Donald Trump: that success is about persuading everyone else that you are successful. When you begin to see all of life as a con, a war of fraud against phoney, then it starts to become not so much comforting as scary that a small but significant share of people suffer no inkling of being an impostor at all. If impostor syndrome is part of the human condition, what, then, of those whom it never touches?

We are all found out sometimes. Not long ago my 14-year-old daughter was refusing to go to school. I had attempted cajoling, punishing, threatening and even screaming at her. None of it was working. As I tried to pry her iPhone from her hands – a penalty that she understands – I shouted, red-faced and ridiculous: “I just hope you understand the price you are paying for what you are doing!” And she said to me, quietly, at last letting go of the phone, “I could say the same to you, Dad.”

At one level it was just teenage rhetoric. But at another level I suddenly understood what had happened: the imposture of my justified authority was being stripped away, and I looked like an impotent tyrant. We all pretend to know what’s best for our kids without really knowing. Some of that knowledge makes sense – dropping out of school really will make their lives harder – but with much of it we are just guessing. All parents are impostors. At a certain point we realise this and judge – and later forgive – our own parents for it.

We also betray ourselves. I recently gave a paper at a conference in Utah on Albert Camus’s view on suicide. I reckoned that I knew what I wanted to say, so I didn’t start working on it until about a week beforehand. But I couldn’t get my thoughts to come together. There was still no paper by the time my lecture began. In Salt Lake City I spent over an hour in front of 30 or so philosophers trying to work through a garbled mess, more or less breaking down as I did so. When the session came to a close, the chairperson of the conference came up to me and hugged me.

Later I realised that my impression of the talk was at least partly an expression of my own anxiety. Having decided in advance that I was a fraud, I found myself believing in my own fraudulence and discounting the many emails I received after the talk praising it. Several scholars sent me their own work on suicide, which again I discounted as polite attempts to make me feel better about my public embarrassment. I was irrationally valuing my own sense of myself above the view that others had of me, and quite possibly buying into a kind of esteem dysmorphia, which is, of course, the very essence of impostorism.

I suspect that the truth is in the middle somewhere. It wasn’t my best talk, but it wasn’t as bad as I feared. Part of my impostorism, I realised, was a weird form of arrogance: presuming that I knew how other people felt about me and my work rather than actually listening to their feedback. And so I confronted another unsettling paradox of impostor syndrome: my doubts about my own self-worth were actually a consequence of me exaggerating my own importance.■