It's a tough question, but every interviewer seems to want to hear the answer: if you could change one thing about your life, what would it be?

Colin and Justin asked me the same thing, but they turned it around to suit their obsession... "If you could change one room in your house, which would it be?"

That threw me. Colin and Justin are lovely lads, exactly the same camp double act that you've seen on Channel Four's How Not To Decorate.

Colin's a charmer, and Justin laughs a lot before flooring you with a sharp-tongued aside.

When reporters ask what I'd change about my life, I always focus on the trivial. I could say, "I'd like to be a billionaire," but that is tempting the gods... they might dump a trillion dollars on me and take away something far more valuable. So I go for the petty choice: "I want to change my hair colour - do you think I'd look good as a redhead?" Applying the same rule to my house, I decided I wouldn't ask for a new kitchen or an extension to the east wing: "I wish you guys could fix up my downstairs loo," I told them.

Justin pulled a face. "It's not blocked, is it?" he grimaced.

"It's mirrored," I explained. "Mirrors, floor to ceiling. Makes the room look a lot bigger, of course, but it's also a little disconcerting, to see your reflection all around, standing there and staring at you."

"I can't wee when anyone's watching," Colin whispered.

Justin looked surprised: "What, not even when it's just you?"

I should have booked a celebrity makeover for my home right there, but the party was buzzing - it was thrown by publishers Jeremy and Carol Robson, to celebrate the launch of Christine Hamilton's autobiography.

Christine knows everyone, and you couldn't grab a handful of peanuts without knocking against three famous figures.

Some of them looked very famous indeed - Marilyn Monroe was there, in the shape of actress Suzie Kennedy... and what a shape!

Suzie is even prettier than Marilyn, and you can see her in adverts all over the place. She stayed in character all evening, blowing kisses and boo-boopee-dooing, while half the men in the room tried to refill her champagne glass.

There was a lot of champagne, by the way, but Christine's husband Neil was making a brave effort to deal with it. They are inseparable - even when she's on the other side of the room, Neil will catch Christine's eye and give her a smile and a wink.

Another lookalike who remained resolutely in character all night was Elizabeth Richard, whose initials ER seemed to predict the role she'd take. There were plenty of cheeky remarks about Queen Camilla, but she brushed them aside with a gracious wave.

Sir Tim Rice sauntered over for a chat. He's always a pleasure, full of conversation and controversial opinions, but too laid back to let his rumblings escalate into rants. He held forth on the importance of England's heritage, and what a rotten shame it was that people couldn't be grateful for living on the best spot on the planet, and what did I think about the rugby, for heaven's sake... but it's all said with a lazy grin.

Tom Conti, the lothario who broke Shirley Valentine's heart (while making half the women in Britain adore him), told me his niece Kath enjoyed fleeting celebrity in the early Seventies when she discovered, after watching me on the David Dimbleby show, that she too could bend spoons.

"It was quite extraordinary, for a time," he remembered. "People couldn't believe it till they saw it. And then the talent just melted away. I suppose it's a bit like a pop song - you hear it, and you can't get it out of your head for weeks, and then one day it's gone. You can't think how it went, what the words are... where do these things go?"

The rooms at the Mandeville were getting heavy with smoke by now, but I started chatting to Timothy Hadcock Mackay, the hotelier who teaches hopelessly disorganised people to seize control of their lives on Channel Four's Time To Get Your House In Order.

Tim's mix of military precision and spirituality fascinated me, so I invited him to join us for a late meal at Wagamama. He revealed how his faith, a mixture of Catholic and Russian Orthodox, sustained him, and told some hair-raising stories about his stepfather, General Eric Mackay, the hero of Arnhem and the figure Tim most admires.

He was a delightful dinner companion, and Hanna and I were speechless when he sent over a massive bouquet the next morning, with a note to say what a good time he'd had.

My mother, who is approaching her 92nd birthday, has been in hospital for the past couple of weeks, and I have been awestruck by the devotion and dedication of all the staff at Reading's Battle hospital. They are dedicated to preserving her dignity as well as her health, and she tells me many times every day how deeply she appreciates their care.

It would be a wonderful, unbeatable standard of healthcare anywhere in the world, even if it cost tens of thousands every day... but it's the NHS, freely available to us all, and it's just a short drive from my home.

I'm with Sir Tim Rice on this one: we don't fully appreciate what outstanding good fortune we have to live in this country.