My daughter-in-law, Rosalind Malthouse, recently produced a widely reviewed and much commented on television series about old people finding their inner youth.

The Young Ones -- not to be confused with Rick Mayall and Nigel Planer's 1980s student sitcom of the same name -- proved that the secret of ageing gracefully lies in keeping mobile, keeping busy and mixing with friends. Which may explain why theatre critics seem to live for ever and rarely relish the thought of retirement.

The actors in the programme were Liz Smith, Sylvia Sims and Lionel Blair, though only one of them, good old Lionel, evinced any appetite for carrying on working. In fact, you got the impression that Li was sitting by the phone all day waiting for it to ring.

But when he was whisked back to the London Palladium, the years peeled away and he choreographed a pretty slick looking routine for a group of girls young enough to be his great grand-daughters.

In the theatre, we've had the Young at Heart choral phenomenon, with pensioners singing songs by the Beatles and Radiohead; the senior citizen version of the Pina Bausch Dance Theatre of Wuppertal; and 77 year-old Sian Phillips playing Juliet in an old folks home version of the play at the Bristol Old Vic.

And tonight, the Young Vic presents a new piece, On Ageing, by the cutting edge company Fevered Sleep. Although the production has researched the process of getting older, it will be performed by young actors.

For years we have been talking about the cult of youth; we now seem to be entering a cult of old age. Joan Bakewell sticks up for seniors all over the place.

And one of the great side effects of the renewed general interest in the First World War is down to the respect and admiration we all felt for the few survivors of the trenches, the last of whom, Harry Patch, died, alas, a few months before he could see Trevor Nunn's beautiful staging of Sebastian Faulks's great novel Birdsong.

During the five minute break in the second act of Birdsong, the stage at the Comedy is filled with a scroll down of the names of dead soldiers, and you could sense the quiet acknowledgement of the house to this moving memorial.

It's a brilliant theatrical equivalent to the novel's re-visiting of the past in the figure of the hero's grand-daughter searching for the truth of what happened, itself a metaphor of the novelist's own writing campaign.

My grand-father was in the First World War and ended his days in hospital, shell-shocked and silent like one of Stephen Wraysford's colleagues in the novel.No-one in our family talked about him. I think I was taken to visit him once when I was very young. He lived his old age in limbo, neither in this world nor the next.

We are fortunate not to have had to serve in such a war in our time, and it's a striking fact that even Lionel Blair is far too young even to have served in the Second World War with my father and his generation.

It is a major problem, of course, that so many of our parents are living for so long nowadays. But we should rejoice that there is no more carnage of the sort "celebrated" in Birdsong, and that Lionel Blair will tap dance his way to a long-deferred burial ground, we hope.