Julie is on the phone. “What it is,” she says, “is just a quick call from Lymeswold.”

At least I think she said Lymeswold, although it could have been Slime Mould.

“In Peterborough,” she adds, as if that explains everything. And do I suffer from any allergies?

I toy with the idea of telling her about the rash that appears on my inside leg whenever I wear a certain pair of jeans, but experience tells me to just say “no”.

So she tries another tack. Who else lives in my house? Am I married? Do I have children? And do they suffer from allergies?

I’m sorry, Julie, but who did you say you were?

“Rhinegold,” is what I hear this time. “We make air filtration systems, and if you can spare 30 seconds to help us with this market research, your name will go into a draw.”

Put into a drawer, more like. And what’s the prize? An air filtration system for two?

“No, no,” says Julie, sounding hurt. “First prize is a camera.”

Now I already have a camera, but what’s 30 seconds between friends? Okay, I’ve known Julie for less than a minute, but her twag sounds so familiar.

“Do you have any pets at all, Mr Newlands?” It’s Newnham, I remind her. And yes, I have two cats. But I’m not allergic to either of them (the trouser problem is something entirely different), and nor is anybody else in the house.

But Julie’s curiosity is undiminished. Do I have floorboards or carpet?

Double glazing or single? And do I rent my home or own it?

Then just as I’m beginning to feel like the Brain of Britain (it’s so nice, knowing all the answers for once), the questioning ceases.

Julie clearly senses my disappointment. “As you can imagine,” she says, “not many people agree to take part, so there’s a good chance you’ll win a camera.”

That’s fantastic news, I say, and try to sound excited. But what possible use can my answers be, given that I don’t have a problem with the air I breathe?

Julie adopts a confidential tone. “Well,” she says, “basically it’s advertising.”

But before I can protest that no amount of advertising will induce me to buy air filtration equipment I don’t need, she hangs up.

And I never did catch the company’s name.