I HAVE long got used to seeing the policemen young enough to be my sons - but now it's the bishops!

And with age develops an increasing censoriousness. I mean for instance, the staff at Mansion House say that, of all the banquets hosted by the Lord Mayor in his year, the one for the bishops is the booziest and rowdiest.

Can this really be me being slightly shocked about this - I who not so many years ago led the assembled scholars of the US Liberty Fund in a carousing chorus of Monty Python's Philosophers' Song?

And it's not just the bishops who are getting younger. A few years back I was chaplain to the Lord Mayor and I was mortified to discover that the Lord Mayor himself is younger than me.

That's one of the things you do when you're approaching the sans everything phase: you find yourself looking closely at your contemporaries - blokes you have cheerfully ignored for the last 50 years. And you think "Old Fred has let himself go a bit. Well at least I'm not as fat as him!" On the other hand, it's a matter of enormous comfort when you can identify someone who shows every sign of thriving when he's even older than you are. A retired banker friend of mine aged 74 - a whole nine years my senior - ran the London marathon.

And you catch yourself making morbid calculations such as, how old was Beethoven when he died, then? And good grief, he was only 57! But Mozart died at 35. Schubert 31. What have I ever done by comparison with them? Suddenly, there is a senescent dawning of hope as you realise that Titian lived to be 98 and when he was my age he had barely started. And Haydn wrote The Creation when he was well into his sixties. Even the old fraud and ladies' man Bertrand Russell lived to be 97.

And it's 53 years since that Whit Saturday when I went to the Roses Match at Headingley and saw Brian Close hit 52 in twelve minutes. And I can hear the man in the crowd - the very pitch and timbre of his voice - as he called out: "Well done, Douglas Brian." And Closey himself is 76 this year. He was a god to me. Still is. But that's another thing: aren't I a bit old for hero worship?

You find it's not all decline. About a year ago I decided to do an MoT on myself and I didn't like what I saw. I had a definite paunch and the beginning of jowls. Eating and drinking too much at City dinners. Right then, I began a regime. The heart-warming aspect of this horrible tale is that I found after a few weeks of bends and stretches and gentle jogs and laying off the booze and puddings a bit, I could run five or six miles without getting out of breath. The weight rolled off and the cheeks de-jowled. I felt marvellous. Of course, the tendency to holier-than-thouness is a fault which certainly gets worse with age and I found myself saying to mates stuffing it away at livery banquets: "You feel much better when you're in shape, you know."

The Bishop of London gave me security of tenure here in the City a few years back and, as it was remarked at the time: "They can't get you out now, Peter - except for senile dementia or gross immorality." I'm afraid it's most likely to be the former. And, as an old pal picturesquely put it: "As you get older, the names drop off things". He should talk. I couldn't remember what you call a bread knife the other day....

* Peter Mullen is Rector of St Michael's, Cornhill, in the City of London, and Chaplain to the Stock Exchange