Aside from height, weight, gender, ethnicity, upbringing and sheer volume of unsightly body hair, there is one fundamental difference between my wife and me. Awareness.

My primary assumption is that nobody ever notices me. I obliviously blunder through life in the hope that my perfectly anonymous face, perfectly anonymous voice and perfectly anonymous manner make me completely indistinguishable from any background I ever happen to be standing against. My wife, on the other hand, is Spider-Man. Drop her anywhere on the face of the planet and, within about 90 seconds, she will be able to provide you with a full annotated transcript of every single thing that every single person within a 50-mile radius has said, mouthed or thought about her. It is a cool trick, plus it means we now have a constantly rotating list of our town’s 10 most racist pubs. Basically, what I’m saying is that I married TripAdvisor.

However, we are parents now, and I have started to get a taste of what life must be like for her. Because, while my root assumption is that you don’t notice me at all, I am absolutely certain that you have noticed my son.

Of course you have noticed him, because he is the funniest, best-dressed, most charming, most perfect little boy who ever lived. Also, he is banging an empty cola bottle against a window, making a noise like a broken sea lion and surrounded by people who just want a moment of peace on the way home from work. In fairness, this might also be why you have noticed him.

It keeps happening. We get on a train, I see people staring at us and I beam back like the proud dad I am. Then, two seconds later, my wife quietly informs me that they are actually staring because they hate babies. Twice in the past fortnight, she has overheard people verbally disparage the concept of children, simply because they have briefly had to share oxygen with one of them.

And this is fine. Everyone should be allowed their own little prejudices. And I am saying this as someone who loves judging people. Give me a new and interesting way to hate you and I will be the happiest boy in the whole world. Waiting for a lift, but you haven’t pressed the button? I hate you. Texting with your keytones turned on? I hate you. Sunglasses indoors? I will actively try to invent time travel specifically to sterilise your father at birth, because that is how much I hate you. So I get it. Judging people is fun.

But a weird instinct kicks in when it is my son who is being judged. Counterintuitively, I have found myself automatically trying to change their minds. When my wife heard some women mutter “fucking kids” at us recently, I perched my son on my lap and let him gurgle and wave at them. When she heard a couple of French teenagers call the three of us whores – in French – I deliberately moved closer to them and played with the boy until, by the end of the journey, they were singing to him.

I am aware that this is utterly obnoxious of me, but it is also a win-win. If they come round (as the French teenagers did), then I have won. If my behaviour makes them even more annoyed (as the women were), then I have also won, because they have got it coming. This is a tactic that will definitely get me stabbed to death before I turn 40, but I can’t help it.

The moral of this story is that people should be free to judge whoever they like. But they should do it really quietly, because my wife is Spider-Man and I’m apparently a massive arsehole.

@stuheritage