Rhodri Marsden: I want to ride my bicycle, but I'm not sure where to put the doilies

For too many years, now, I've sat on my pendulous behind while precious global energy reserves have been used up to propel me from A to B. I can't have the melting of glacial ice on my conscience, so I decided to get a bike. I consulted a cyclist friend, who looked me up and down and immediately recommended something that you might describe as très sportif if you were French and really sarcastic.

When I posted a picture of it on Twitter, some stranger said that it looked as if it had been nicked off the set of Call the Midwife. It has a shiny bell, should probably have a basket and would be complete with a floral parasol and some doilies draped over the handlebars. I love it.

But there's a niggle. I'm not sure that I'm the kind of person who's suited to riding a bike, and I sense that everyone else senses that, too. This isn't my first venture into cycling; as a teenager I'd speed through the streets of Dunstable on a 10-speed racing bike with a bassoon tied to the back – which, coincidentally, is now one of the challenges in Total Wipeout. But from the moment the assistant in the bicycle shop smirked and referred to me as "buddy", I felt unsettled.

It's possible that he does that to everyone, even the local constabulary, but it transformed me into an unconfident consumer, and I hate that. Gullible dunce meets contemptuous expert. He told me that my bike had no integrated rear-wheel lock; I looked at him and almost said, "Is that good?", but just managed to shut myself up.

This lack of confidence has extended to the actual cycling. It's pathetic. If traffic's too heavy I get off and walk. The first time I had to lock the bike up, I realised I'd never operated a heavy-duty lock before and didn't know what to do. I pretended to be on the phone until no one was around and spent five minutes figuring it out.

I don't know why I fear people looking at me and thinking "ha ha, he's not done that before", but I do, whether I'm locking a bike, putting money on a horse, driving into a car wash, administering mouth-to-mouth resuscitation or doing the lambada. I reckon all five should be on the national curriculum.