Back when I was a 17-year-old-high school pupil, my classmates and I would go out every weekend to the local bar in our home town.

We would do our best to slip in unnoticed and lived in fear of being asked for ID and our underage status being exposed.

Our tried-and-tested method to avoid detection included piling on make-up to make ourselves look older, wearing simple black dresses so we didn't stand out, and attempting to gain entrance to the bar only in small groups of twos or threes. Every Saturday night, tension was high as we prepared to run the gauntlet past the bouncers.

When I turned 18, my passport was my most prized possession as it provided guilt-free access to a world of bars and clubs. Bizarrely, I have been asked for ID far more frequently since actually coming of age thanks to the Think 21 and Think 25 campaigns which were introduced in licensed premises and bars in an attempt to combat underage drinking.

So now I find myself, at the age of 29, unable to buy alcohol a lot of the time without having to prove my age to shop assistants by showing my ID. For a while I moaned about how inconvenient this was but as I approach 30, I am starting to see the benefits. Youth is praised in our society so to be frequently mistaken for being four years younger than you actually are is a nice little ego boost.

But earlier this month, it all stopped and suddenly no-one bothered to ask for ID any more. I looked in the mirror and wondered what had changed? Was there an errant grey hair or fine line that I could blame for this change? I fretted about this to an embarrassing degree until finally, a fortnight later, I was asked for ID again and everything was alright with the world.