Susan Boyle is by no means the first famous entertainer to beat a retreat to the Priory. But she has certainly moved from discovery to exhaustion with exceptional alacrity. Poor lady. It was all too much for her.

No wonder. "It" was always savage. From the beginning, the "novelty" of Boyle was that she did not look or act like she could sing (however that looks), but could. The audience and the judges in Britain's Got Talent were all geared up to have a laugh at Boyle's expense until she opened her mouth and confounded her would-be critics. They didn't even bother to hide their ignorant prejudice.

If Boyle had not been correct in her own assessment of her singing ability, her public humiliation would have been brief, but it would have been public humiliation nonetheless. That, apparently, is wholesome family entertainment. It is why Simon Cowell's talent shows depart from the shows of the past, and make a great fuss about broadcasting auditions.

Instead of ridicule, Boyle attracted curiosity – lots of it. A dotty, homely, middle-aged woman was very good at something. Hold the front page. Boyle's back-story – a lonely lifetime in a small village, given purpose in her isolation by her local church – promised a wonderful tale of triumph over adversity. What, exactly, that adversity might be, was paid little heed.

Why, after all, would the media encroach on a woman's privacy, by plastering that she had learning difficulties on their front pages? That might have interfered with a schedule that involved encroaching on her privacy in the usual way, by hanging around her home taking photographs, and publishing those showing her with her trouser zip unfastened.

And why would the executives at Britain's Got Talent have asked the media to lay off either? Boyle's appearance – in both senses – was getting them international attention. What canny television apparatchik would have risked complicating such golden publicity? Much better to let the "fairy-tale" run, and let the whole world believe that Boyle's sudden fame was a triumph of the extraordinary-ordinary, a home-spun comment on how obsessed the silly entertainment industry is with youth, glamour and surface, instead of sheer, raw talent.

But here's the sting. Being exceptionally good at what you do is only a little part of the complicated business of being famous. That's why so many people achieve fame without, seemingly, being terribly much good at anything. That's why, at 48, Boyle was still languishing in West Lothian dreaming her dreams.

You do have to be reasonably attractive to be in the public eye, especially if you are female. If you are not, it will be made an issue of, not just by the media but also by potential audiences.

If you have a very strong character, you may be able to withstand such criticism. A strong character can mean all sorts of things. But it helps to be single-minded, hard-working, determined, resourceful, willing to put up with disappointments, focused, confident, socially adept, charming, able to create an impression, manipulative, shrewd, opportunistic or able to identify and follow good advice.

You can have many of these qualities, and depending on how much you have of some, you can get away without quite a number of others – providing you don't much mind ending up in the Priory sometimes yourself, or becoming a monster of egotism. When someone becomes justly celebrated, but is clearly still decent, unaffected and "normal", we recognise that this is truly remarkable.

Life, let alone "the pressures of fame", is too tough, and competitive and ruthless for fragile people, whatever their talents may be. It was always a nasty trick – against not just Boyle but against her naive supporters as well – to pretend that matters are otherwise. It will be a great thing if Boyle can salvage an interesting future that she can cope with from the ruins of her 15 minutes. Plenty before her have not.