Christina Patterson: When old age is the time of your life

The other day, in a house in Prague, I met an extraordinary woman. The house was the home of Alfons Mucha, the Czech artist who met Sarah Bernhardt in Paris, and whose posters for her performances made him one of the leading lights of Art Nouveau. The woman was his daughter-in-law, Geraldine. She met his son, Jiri, at a wartime party in 1941 in Leamington Spa. You can see why he fell for her. Geraldine Mucha is attractive, bright and funny. Next month, she will be 92.

To invite a bunch of strangers into your home, and show them the treasures that surround you – the posters, the pictures, the photographs, the piano that Gaugin played (according to a photograph on the mantelpiece) wearing only a shirt, the musical keyboard that had hidden drawers for Sarah Bernhardt's make-up – might, you'd have thought, be quite activity enough for a woman branded a "pensioner" more than 30 years previously. In fact, the stairs would be enough. I was huffing and puffing, but she was leaping up and down them like a young gazelle. Geraldine Mucha is not, however, just curator of a real-life Bohemian rapture and keeper of an artistic flame. She is, she mentioned casually, a composer.

It was her father, a concert singer missing in action in 1917 when she was born, who introduced her to music. When he returned, rescued by Belgian peasants, his voice wrecked by mustard gas, he became Professor at the Royal Academy of Music. It was there that he – and she – met Rachmaninov, Elgar and Strauss. And when her husband was imprisoned by the Communists for his links with the West, she started composing, "to take my mind off things". Sixty years later, she is still composing, and her work is still performed by the Czech Philharmonic. "It keeps me busy," she said.

Last week, I went to the opening of "As Time Goes By", a spectacular new work by Howard Hodgkin, and his largest yet. In the past month, I've interviewed two other super-energetic 70-somethings, Peter Hall and Philip Glass. Mere children compared with Mrs Mucha, of course, but all producing work that the vast majority of younger artists couldn't hope, in a lifetime, to achieve. And younger, as we all know, is better, younger is sharper, younger is sassier, younger is cool.

It's a salutary reminder, in fact, in this age of the cult of youth, to see that much of the best, most interesting, and most genuinely innovative artistic work is produced by people who our society wouldn't give a job to, people who'd be tossed aside before the interview stage because of the first line of their CV. But there's a much bigger human lesson, too. The secret to eternal youth is surely not to drink your own urine, or smoke 60 a day, or whatever else some 120-year-old peasant on the Mongolian Steppes has decided, but to pursue, to the point of near-obsession perhaps, a passion.

The point of a passion is that it's something outside yourself. It doesn't depend on the smoothness of your skin, the sharpness of your cheekbones, the ripeness of your buttocks, or the pertness of your breasts. It depends on the functioning of your brain. And while none of us can insure against dementia, it will surely help to have a brain that's still engaged with the world, a brain that persists in believing, in spite of the body's mounting betrayals, that the world is, in the words of MacNeice's wonderful poem, "Snow", "suddener than we fancy it", "crazier and more of it than we think" and, more than anything, "incorrigibly plural".

May it happen for you. May it happen for me.

At last I've been to the opera and seen the light

As a bit of an opera dimwit, I have to admit that my occasional trips to a Cosi, or a Figaro, or a La Bohème, tend to be characterised by flashes of intense pleasure in a fog of confusion. It's all very lovely, but just what is going on? But after a trip to Glyndebourne at the weekend, I think I've seen the light.

What costumes! What drama! What tragedy! And that, of course, was off the stage. Away from the pathos of rain-sodden picnics, a tale of love, death, war and betrayal was unfolding before us, a tale in which Julius Caesar was, for some reason, played and sung by a girl and Cleopatra was played by – well, a goddess.

I had never heard Handel's Giulio Cesare, I didn't know anything about the 18th-century prediliction for castrati, and I sniggered at the tortuously complicated plot when I printed it out on Google. But it was, quite simply, riveting.

The set, costumes and lighting in David McVicar's production (which first appeared in 2005) were fabulous, combining 18th- century grandeur with Bollywood wit and charm. The show was stolen, however, by Danielle de Niese, an Australian-born soprano whose minxy, magnificently sultry and, of course, exquisitely sung, Cleopatra had the entire audience electrified. When Sarah Connolly, as Caesar, snogged her, you could feel the entire audience practically panting with desire.

Land-line cold calls are bad enough...

When my landline rings, I know who it is. It's either my mother, who believes that a mobile phone is something to be switched on only for special occasions, and then by wrestling with the button as if it were the stone blocking the entrance to Christ's tomb, or it's someone offering me a wonderful opportunity to try something new.

The "something new" is never, alas, a free holiday to the Bahamas, or a meal at a local restaurant. It's usually a burglar alarm or double glazing, which I will be offered free for a trial period, etc. I try to be polite, but I always feel invaded. This is my home, I want to scream. I was in the loo, for God's sake.

Well, now we can look forward to such intrusions all the time. A company called Connectivity has bought details of about 40 per cent of the mobile phones in the UK, so we can be pestered by people wanting to sell us things any time, any place, anywhere. The point, surely, about a mobile phone is that it allows you to maintain contact with a carefully selected group of people, chosen, presumably, because you like them.

It can only be a matter of time before our dinners with friends, and strolls in the park, are accompanied by offers of breast enhancements, sudden millionairedom in Nigeria, and super-strength Viagra. Connectivity indeed.