Last week, a young colleague of mine brought his new girlfriend into work for the first time.

When she walked into the room, I was caught on the hop.

I had seen photographs of her, but on this occasion, I didn't recognise her at all. It was daytime, and she was wearing jeans and a top, with her hair tied back – and crucially, wearing no makeup.

This wasn't just a case of someone looking a little different. This was a total and utter transformation.

She was unrecognisable.

There wasn't even the slightest resemblance between the two. I didn't know makeup – plain, normal makeup – could have this type of effect.

This particular instance struck me hard, because the girl in question was only 18; and on the occasion of our meeting, she looked every bit of that, as she should.

But the photographs showed someone in their mid-twenties, possibly more, with a worldly-wise expression and the ubiquitous duck-pout that makes me want to stick a goldfish between their lips every time I see it.

In the photographs, she was hard and polished. In the flesh, she was a very sweet young girl.

I know every teenager wants to look at least five years older than they really are.

I was the same, caking my face in cheap cosmetics and brandishing a borrowed driving licence to sneak into the over twenty-five section of Time.

Now, I find myself browsing the anti-ageing sections of the makeup counters, desperate to peel the years away instead of adding them on. It seems that whatever age we are, we're never really happy.

However, times have changed. It's not just the 18-year-olds who brandish their contour brushes with such aplomb.

Girls as young as thirteen and younger are so appearance-savvy now that their handbags are stuffed full of cosmetics; their hairstyles are neat and intricate and they spend their spare time watching makeup tutorials on YouTube.

This generation is different. Tinted lipglosses and hair mascaras just don't cut it. It has to be the best – and most expensive – products, applied with professional skill.

Gone are the days of hapless experimentation, where you'd venture out with crooked lipstick and circles of blusher that would make a clown wince.

Maybe I'm just jealous they're not going through the same hideous teenage learning curve that I experienced. But it also saddens me a little.

There's more to life than looking perfect all the time, and we, as society, should be reinforcing that message.

At present, we're teaching teenage girls a worrying lesson: that appearance is everything, that perfection is the goal, that following trends is desirable and that image matters more than reality.

So who's to blame? Maybe it's the ready presence of cameras at every turn: smartphones that can Snapchat your fashion failures to friends in a click.

Who doesn't desire to look their best in front of a camera? In a world dominated by fish-gapes and duck-pouts, it's small wonder that the Instagram generation feel the need to be perfect at all times.

I cannot imagine the pressure on young people now when they know that images will be shared, circulated and criticised over so many platforms. Bring back the days of the disposable cameras, when you had twenty-four exposures and all unflattering pictures could be stuffed in the nearest bin without second thought.

There's nothing wrong with the desire to look nice, and I'm not saying that teenagers shouldn't wear makeup. That would be hypocritical and slightly ridiculous.

What I am saying, however, is that we should do everything we can to lessen the pressure of looking perfect.

The natural beauty of youth should be allowed to shine through, and enjoyed for every moment that it lasts.