Another birthday, another year older. Which probably wouldn't have been so bad to deal with had I not overheard my four-year-old daughter excitedly telling a school friend that "mummy is 97 today".

There comes a point in this ageing business when you've turned 21 again so many times that you have started to lose count - and birthdays have become more about a chance to have 24 hours off washing, cooking and other chores than the celebration of being another year older (albeit hopefully - or at least possibly - wiser.)

Overheard:

Acquaintance: "I'm going to be 25 on Friday. I'm so excited I can't wait."

Old friend: "I'm going to be 45 on Friday. You won't tell anyone, will you?"

Modern childhood now ends at the age of 12

And this is where I am.

How different this is from my child, for whom time can't whizz by fast enough and every passing season is worn like a badge of honour as it's added to the tally - four and a quarter, four and a half, four and three quarters and then the daily countdown to the momentous milestone of being five, and all the kudos and grandeur that entails.

For a youngster, childhood seems to last an eternity, stretching out forever when you're always waiting to be old enough or big enough to do/ use/ wear something that seems impossibly exciting or glamorous (at least until you actually do/ use/ wear it).

For a parent, childhood seems to slip away in the blink of an eye - one minute a mewling infant, the next starting big school and no doubt five minutes down the line leaving home to make their own way in the great wide world.

Time appears to be zooming by far faster than it ever has before, and I'm clearly not the only one to think so. In fact, a report published last week declared that modern childhood now ends at the age of 12, thanks to "a toxic combination of marketing, media and peer pressure".

"Isn't it terrible?" we all said when we read it, bristling with disapproval and longing wistfully for a more innocent age. "They are expected to grow up so fast these days. It wasn't like that in our day."

But in some ways, actually, it was.

After all, it's no new thing that under Jewish law 12 is very the age a girl becomes batmitzvah - a rite of passage that does indeed mean leaving childhood behind to become a woman, with all the responsibility that this entails.

If this is what growing up means I can deal with it. If it's about pre-pubescent youngsters obsessing about Justin Bieber and the latest mobile phones then, yes, I can see that I'm going to struggle.

But there will be time enough in the future to worry about teen stars and technology. For now, I shall focus on proving that the playground gossip set in motion by my darling daughter is nothing but scurrilous rumour - and there is actually a very long time indeed until my 97th birthday.