'I once met someone who was afraid of layers. Layers! I asked her what would happen if she was served Walls Viennetta for pudding. She went pale'

Over Halloween, a "phobia store" opened up at the London Bridge Experience (the agglomeration of tourist attractions and emporia that have sprung up round the city's old dungeons 'n' plague pits, to prove once more the truth of the ancient maxim that the suffering of ages + time = Perspex keyrings at £2.50 a pop). It allowed you not to buy a phobia, as those of you who habitually let your commitments to semantic orthodoxy override your commonsense might have assumed, but to face your fears – spiders, rats, snakes, whatever – by getting up close and personal with the objects of said fears, thereby overcoming them. And, ideally, buying a keyring to celebrate on your way out.

I couldn't go myself because my own phobias include not just hair*, walking barefoot on carpet** and touching the underside of bags***, but also sites of historical interest crawling with young actors in period costume who are slowly being driven into madness by the flickering image of Ben Whishaw that dances on the inside of their eyelids whenever they try to sleep.

But also, I can never get wholly behind any drive to cure people's phobias. For a start, they make great conversational fodder at parties. Personal, but not too personal. Unlike discussing someone's job or children, discussing a phobia won't lead to sudden outbursts of uncontrollable weeping. If it were that severe, they would have stayed at home for fear of stray hairs landing on their jumpers (or, you know, whatever), so you're quite safe. And, unlike discussing someone's dreams or star sign, it is not pulverisingly boring. It is, in fact, fascinating.

You never know what dark fears and hatreds are crawling around inside people's brains. Forget spiders and snakes. Boring! I once met someone who was afraid of layers. Layers! I asked what would happen if she was at a work dinner and they served Wall's Viennetta for pudding. She went pale and shrank back into her chair. "They wouldn't!" she said, horrified. "They couldn't!" Actually, I don't think she's been out since.

Within my own circle of friends, I have two who are afraid of buttons, one who starts climbing the curtains if anyone puts metal – money, say, or a belt with a buckle on it – on the bed, another who has to be talked down from a ledge if she spies crushed up paper anywhere nearby. And I have spent my life checking out pubs, shops, hotels and restaurants for my best friend, who has always had a quite spectacular fear of stuffed animals. I once overlooked a tiny robin, nailed to a Victorian mahogany perch in the farthest recesses of a Cotswolds hostelry. It was barely visible to the naked eye. Sally walked in and leapt straight backwards to Carlisle, leaving only a strangulated cry behind.

The best thing about phobias, however, is that they are superb levellers, and a powerfully unifying force once shared. You don't need to walk a mile in another person's shoes. You just need to hear that they, too, are secretly consumed by fear of a wholly innocuous entity. Et voilà, the acknowledgment of your shared madness and humanity. I asked about the Viennetta in a spirit of curiosity, not mockery, I promise. Who am I, who cannot even name the horrors that would befall me if I took off my shoes in a strange house, to laugh at anyone? A hatred of the unblinking stare of dead animals might be more immediately comprehensible than a hatred of buttons, but all phobics are members of a single brotherhood – the brotherhood which understands that inanimate objects want us dead. Stay strong.

* Loose; not attached to head; roaming free and seeking to wrap itself around my fingers; I've actually made myself retch, typing that. And I hope you're happy.

** And now I'm crying as well. Thank you so much.

*** You don't know where they've been and therefore you could die. Fact.