There comes a time when you realise that pop stars and celebrities only exist to remind you how old you are getting. What? Katy Perry is only 25? And how is Scarlett Johansson only 26? And so on, before you begin yet another revision of your ambitions that ends with the quiet realisation that your oft-practised Oscar speech will never be used, nor will you ever replace Nadine in Girls Aloud. Bummer.

Recently, things have got a little severe in this department. Celebrity – especially music-based celebrity – is becoming infantilised. Perry and Johansson and so on are now to be put out to pasture to make way for the frighteningly young ones chasing behind them. Musician Justin Bieber (16) is on the cover of the current edition of Vanity Fair. Recently, the singer behind the global hit 'Whip My Hair', Willow Smith, graced the cover of the Sunday Times Style magazine. Willow was born in 2000. Thirteen-year-old Tavi Gevinson has been plying her trade as one of the world's most high-profile fashion bloggers for two years now.

One of the most ridiculous things about this new era of evil-baby pop culture is that we give credence to it beyond viewing its poster-children as amusing little minstrels for kids to scream at and adults to shrug perplexingly at before buying overpriced tickets to see them in the O2. The industry of child entertainment has always existed, but its audience has until now been confined to children. Nobody put Barney the Dinosaur on the cover of Vanity Fair and asked him what his inspirations were. Today, it's assumed that just because a load of toddlers think some gooey-eyed bowl-haired Canadian asexualite (I'm talking Bieber here) is a dreamboat, adults are meant to endorse him too. Sure, he's a phenomenon, and his success is yet another example of how lucrative the tween and young teen market is, a path that High School Musical laid ahead of him. But why do we stand for grown-up media being infiltrated by little people who a couple of decades ago were being manufactured in Jim Henson's workshop?

Child stars have always been around, but people such as Shirley Temple were figures of fun and novelties. Michael Jackson broke that mould, but in fairness, he was the greatest pop star of all time, so there's an exception to every rule. The idea of taking kids who only possess a dubious amount of talent seriously as artists is a complete joke. Sure, Mozart was 14 when he wrote his first decent piece of music, the opera Mitridate, re di Ponto, but I'm not sure you could compare Justin Bieber's hit 'Baby' (sample lyric "And I was like / Baby, baby, baby oh / Like baby, baby, baby no /Like baby, baby, baby oh") to a musical war drama set in the Crimean port of Nymphæum in 63BC.

I've just watched a video of a very young Madonna auditioning for Fame. She says she's 21, but she's actually 23. But in the '80s, 21 was young. Today, if you don't have an autobiography and your own perfume out by the time you're 21, you need seriously to be thinking about firing your agent. Madonna was 25 when she had her first crossover hit with 'Holiday', (not 'Lucky Star', as Bridget Jones would have you believe). Twenty five. Rihanna (who has already sold 60 million records, aged 22) won't be 25 until 2014. For the most part, this new gaggle of famous kids in a grown-up world is an American issue. America has always loved its child stars, whereas over this side of the water, we like our fame middle-aged. America gives us Justin Bieber and Miley Cyrus, we give them Susan Boyle and Gordon Ramsay.

Scratch deeper and one realises that this issue is largely about the infantilisation of ourselves. In the latest issue of French Vogue, outgoing editor Carine Roitfeld saved her most controversial editorial shoot until last, splaying children in adult poses and clothes across her magazine's pages.

Frankly, the first word that comes to mind perusing it is 'sick'. Like Bieber, Willow, Tavi and co, this is about the inversion of inspiration-seeking as much as it is about fetishising super-youth. A sizeable portion of adults are now beginning to look to children for inspiration in everything from pop songs to fashion writing.

Youth will always be an obsession for as long as the passage of time is around (so, for quite a while, then), but the desire to remain youthful seems to be crossing over to a desire to be childish. Let's grow up.

Hold me...

Everyone in newspaperland was very shocked and saddened to hear of the closure of the Star Sunday.

It's a crappy start to the year for the 17 permanent staff and various freelancers and shift workers. Hopefully they'll all get gigs elsewhere soon.

Best of luck to them.

Thrill me...

Only 267 days until Rihanna in the O2. Not obsessed, honest.

Kiss me...

The best moment of the year so far is the existence of The Amanda Brunker Sofa Collection, a celebrity collaboration that the acronym WTF was invented for. Bring on The Derek Mooney Food Processor Anthology and the David Davin-Power Shower Rail Compilation.

Kill me...

The 22-year-old singer Jessie J 'won' the industry-chosen BBC Sound of 2011 list, an annual anointing of who music journalists and DJs think will be 'big'. It's a pity, then, that she's the most dated, diluted and least interesting in the top 10. Which, of course, is all part of the reason why she will in fact be 'big'.

umullally@tribune.ie