When I was 15 years old, I was travelling up the motorway with my sister-in-law Naomi and her three small children. We stopped at a service station and one of the little girls declared that she wanted to play Ring o’ Roses. “OK!” said Naomi, and there, right in the middle of the concourse, they all joined hands in a circle and started to sing. “Come on!” one of them said, holding out her hand to me so that I had no choice but to join in.

It was the most appallingly embarrassing thing that had ever happened. I thought I might actually die. If this is what you have to do when you have children, I thought as we all fell down, then I will never become a mother.

Fast forward 15 years, and I became a mother. It took me only a matter of days to lose all inhibitions about looking foolish in public. Ring o’ Roses in a service station now seemed like nothing. I would quite happily have performed a one-woman cabaret show in the middle of Oxford Street if that was what it took to keep the baby happy.

Not only did I become perfectly sanguine about doing a whole range of extraordinary things I would never have considered in the past, but my ability to navigate the ordinary adult world became compromised in all sorts of unexpected ways, and remains so to this day.

For example, I will find myself swaying gently from side to side because someone near me is holding a baby; waiting for the green man before crossing the road, even though I am by myself and there’s not a car in sight; moving a cup away from the edge of the table, when it actually belongs to my husband who probably already has the cup situation under control.

I am far from alone. One of my friends, for example, has unthinkingly cut up the food on the plate of the grown-up sitting next to her; and I’ve lost count of the people who have exclaimed ‘Look, a plane!’ or ‘Look a digger!’ and realised they were talking to another adult — in one case to a government minister outside the Houses of Parliament.

Small children and the baggage that comes with them take up such an extraordinary amount of physical and emotional space, it’s scarcely surprising that they monopolise even the parts of the day when you are trying to be a person in your own right, as opposed to a parent.

When I used to work in an office, I would regularly reach into my handbag and pull out something completely incongruous — a toy car, for example, or a half-eaten bag of fruit flakes, or once, a whole carrot. This did not enhance my reputation as a razor-sharp publishing professional, which may have something to do with why I’m now a freelancer. It’s much less dangerous to work from home where no one looks askance if I fail to notice that I am still wearing the necklace made out of pasta that my daughter gave me that morning.

Naturally, the more serious and formal a job one has, the more potential there is for embarrassment when your efficient veneer is shattered because of your children. My barrister friend Adam, for example, turned up at court once with a Mr. Tickle sticker attached to his suit.

Adam has a Twitter account on which he debates the pressing legal, political and human rights issues of the day. His toddler daughter recently sent a tweet to his 30,000 followers, in which she shared a link to a Giant Disney Princess Rapunzel Castle.

This shows that even if we ourselves are able to separate our family and work lives successfully, our children tend to make sure that doesn’t happen. Mobile phones are a clear source of peril, because they bridge the boundary between home and work like no other object. One friend’s child changed her ringtone to a quacking duck, which then went off at a meeting at which 12 MPs were present; another used her iPhone in front of her colleagues, only to discover that her kids had secretly reprogrammed Siri, changing her name to Idiot. “Hello Idiot,” said Siri.

It seems to me that there is an obvious lesson here, which is to stop pretending that there is an artificial boundary between being an ‘adult’ and being a ‘parent’; because there isn’t, and pretending that there is will only make us look more silly.

Naomi (of Ring o’ Roses fame) carries wet wipes in her handbag at all times. This wouldn’t be worthy of comment, except that her youngest child Anna is now a 28-year-old rabbinical student.

Once Anna has semichah, I don’t know if Naomi is going to offer to wipe her hands and face before she gives a sermon — but I do hope so.

@susanreuben