Paul Barnes was inspired when he saw Sir Ian McKellen in Norwich recently. It made him think that being an octagenarian was in fact the perfect age to be

This year, with a bit of luck, I shall turn 80. No candles will be lit until July, but I've already had the most remarkable birthday present and what a corker it was, a bravura solo presentation of reminiscence, gossip, poetry and bits of The Bard by a noble knight of stage and screen. Thank you, Sir Ian McKellen.

The gift wasn't exclusively mine. I shared it with a Norwich Playhouse audience consisting largely of other members of the bus-pass brigade who become octogenarians this year. Sir Ian turns 80 on May 25, though you'd never know it from his performance - poised and full of zest, striding the stage from side to side, from front to back. His agility reminded me of WC Fields's envious admiration for Charlie Chaplin: "The son-of-a-bitch is goddamn ballet dancer!"

Ian (he prefers to drop the "sir") will need that energy. Come September he will have taken the show to 80 venues across England, Scotland and Northern Ireland, in celebration of his own birthday.

Except for a large box plastered with theatre stickers, rather like an old-fashioned theatrical hamper, the stage is empty. In a pool of brightness Ian flourishes a fat copy of Lord of the Rings. In a thunderous voice he tells the story of the battle between the Balrog and Gandalf on the bridge of Khazad-dum. Then he plucks from that box the huge sword that Gandalf wields in the film. Later, that magic box yields more props including a table, a folding film-set chair and the complete works of Shakespeare.

Lord of The Rings is quite a book, over one thousand pages. Yet since the film every other person he meets claims to read it every year. While making the film in New Zealand, he met Sir Edmund Hillary. Extending a huge hand, the conqueror of Mount Everest booms proudly: "I read Lord of the Rings every year."

"Has anyone here been to New Zealand?" Ian asks. A few hands go up. "Has anyone ever been on a New Zealand postage stamp?" Aha, there are no takers; the honour is his alone.

Born in Lancashire, young Ian's enthusiasm for the stage was hatched and nourished in Bolton; he had three theatres to choose from, all gone now. He absorbed everything: plays, both serious and trivial, variety and pantomime. In his diary he wrote: "Anything to do with the theatre pleases me." He started acting in earnest at school, where his teacher told the cast "Of course, young McKellen here has grease-paint flowing in his veins."

Bolton is on the tour itinerary, and so is the Belgrade Theatre, Coventry. That's where he got his first professional job in 1961, in rep at eight pounds, ten shillings per week. Three years later he got his Equity ticket and headed for London. Maggie Smith spotted him and was impressed enough to persuade Laurence Olivier's new National Theatre company to take him on at the Old Vic.

It was at the Old Vic that, years later, the spirit of panto crept up to push him on stage as Widow Twankey, eyebrows arched, lips pursed and brimming with innuendo. Now, with only a headscarf plucked from the box, here's the outrageous Twankey again, gurning and flouncing for us.

"Do you think we could sign him up as dame for Jack & the Beanstalk at Gorleston?" whispers Helen McDermott. She's nowhere near 80 but here as my "carer". "With his energy and looks you could sign him as Jack," I said.

We octogenarians are all war babies, yet Ian makes no mention of the war - but before the show and in the interval the audience summoned up recollections of air raids, absent fathers in uniform, terrifying War Office telegrams, the shortages, rationing and queues - and no bananas. One woman said her mother was always telling her what a glorious treat a banana would be. Then, when she peeled her first one in 1945 and said she didn't like it, her mum was mortified.

And after the war older brothers were being called up to fight in Korea, Malaya, Aden and Cyprus, and the queues and rationing continued. In 1947's winter we shivered as coal was frozen in the railway trucks; at school we had tests and exams, including the eleven-plus and then the GCEs; we might have shed a tear at maths but we persevered. Meanwhile, the prospect of National Service loomed.

This was no time to be a ninny. Stress and pressure came from all directions. There was no point in whining; we just coped, and learned. After 80 years we're still coping, still learning, and we're not stopping yet.