A colleague of mine went to visit his son in London last week. The son, who is probably the same age as me, perhaps a couple of years older, lives a rather Bohemian lifestyle that revolves around residing in a work-living space in somewhere terribly trendy, creating works of art for the edification of the capital's culture vultures during the week and surfing off the coast of Cornwall at the weekends. Which, it has to be said, sounds like a lot of fun.

The sort of fun, however, which is generally not conducive to a life of parenthood. Not that I'm bitter or anything - I can't surf. Besides, some of us choose to have children and some of us don't. It's just that those of us who do often feel that we've been shunted off to the sidings of life, and acquaintances who have either not got around to sprogging or have no desire to sometimes appear - dare I say it - a little smug.

It used to be that parents were roundly condemned for their perceived air of superiority but no parents I know ever exhibit any tendencies to look down on childless people - why would we? Besides, we're too exhausted from sleepless nights.

The cardinal error many childless people make is thinking that us parents have never known what it is like to have fun. Well, guess what? Just because we have chosen to wear matching T-shirts with "Mum" and "Dad" written on them and sit in a bath of sick and poo for the next five years doesn't mean we didn't have a bit of a life before.

"I don't know how you do it," simper the childless ones as you recount a night of precisely three hours' sleep spent in four different rooms in the house. "I just couldn't do what you do." Meaning, of course: "Good God, that sounds an absolutely awful way to live a life, thank God I'm going for a nice meal tonight, probably followed by a few drinks in a cafe bar and, if I'm extremely lucky, a drunken fumble in the cab on the way home."

Let me tell you a secret. This is how we do it: We try our very best to ensure that, despite what other people think, we are still the same human beings we were before, with the same interests, the same passions, the same lust for life, it's just that we have kids now and don't get out as often as we'd like.

Priorities do change, obviously. Once upon a weekend, I would have spent my time cruising from shop to shop, hunting for something to wear that night to the pub.

Nowadays its getting the kids' feet measured at Clark's and ensuring there's plenty of milk in the fridge. No contest, right? Well. On Sunday we went to Sainsbury's and found ourselves in the children's clothing aisle. I caught myself absently rubbing the hem of a small denim dress and glanced around. Nearby were a young couple with a child in a pram, less than a year old. The bloke had long hair and a knitted hat on, had the look of "rocker-until-recently" about him. He too was examining the quality of an item of children's clothing.

A look passed between us. I couldn't say for sure what it meant, but in the split second our eyes met, we knew. Knew that even though we were standing in Sainsbury's on a Sunday afternoon, genuinely interested in whether a piece of supermarket clothing was of the requisite quality to clothe our progeny, that wasn't the measure of us. Knew we were human beings with all the complexities that that entails, and knew not only were we not "just parents", but being parents paradoxically added an extra dimension to us, making us fuller and more well-rounded people. Knew that it would be - that it was - all OK.

Either that, or he was a store detective and thought I was going to nick the dress or maybe just wondered why some weirdo was staring at him. You never can tell what people are really thinking.

Which, I suppose, is my whole point.