Lesley Brain looks teasingly familiar as she opens the front door to her spacious Tetbury town house.

Dark hair, no-nonsense glasses and coolly speculating intelligence… Wait a minute… Isn’t she that English teacher who once put the fear of God into me at school? Or the fierce receptionist who wouldn’t let me near the doctor that time I pretended to have an appointment but didn’t?

“People come up to me all the time now and say, ‘Ooh I know you!’” she says, leading the way into a 25 Beautiful Homes sitting room. “What they mean is that I’ve been on their television every evening, albeit for 11 days. They imagine they have a two-way relationship. That I am their friend.”

Actually, I wasn’t talking about her brief appearance on Big Brother, Channel 4’s blockbuster reality TV show. She genuinely does look familiar. But she has hit on a modern phenomenon. An Andy Warhol-esque observation about fame. We really are a mite befuddled nowadays about the difference between friend and celebrity.

But in truth, not many of us know anyone quite this posh.
Despite exaggerated Channel 4 claims, Lesley Brain might not be on matey terms with Charles and Camilla (though she did once go to Highgrove for drinks); she might not have been a Cambridge don (though she was formerly married to one), but she is clever, well read, feisty, humorous, entertaining and, most important of all on the poshometer, belongs to Tetbury WI.

Somehow you can see how Lesley stood apart from the usual Big Brother applicants, such as 23-year-old Laura (known as ‘Wangers’ because of her large breasts); or 22-year-old unemployed Charley, whose moving, carefully-honed life philosophy is ‘Celebrity, celebrity, cash, celebrity’.

No, honestly, I’m not making this up. In fact, if you still think Big Brother refers to Nineteen Eighty-Four by George Orwell, I’d seriously recommend you put down this article now, and tackle The Times Killer Sudoku instead.

For we’re talking about Channel 4’s voyeurism-fest, where up to 20 housemates, with nothing discernible in common and nothing better to do, are locked in a specially-constructed house and filmed 24 hours a day. Over a period of 13 weeks, viewers vote on who should be evicted and who should ultimately stay to win a £100,000 cash prize. Not so much Nineteen Eighty-Four as Lord of the Flies; more Roman circus than Gerry Cottle’s.

When the Big Brother production team held their auditions for applicants for the latest series, they must have thought all their luckiest planets were in conjunction when Lesley walked in: she’s as far from the usual class of contestants as Ascot is from Watford.

“Yes, I knew I was gold dust to them,” Lesley admits. “I could see why they wanted me, and they knew exactly what they were looking for. Last January when I went for the open audition in Cardiff, they got us all to fill in a 48-page questionnaire. I’m the only person in the world who adores questionnaires - I stop people in the street and ask to fill them in - so it was no great hardship for me. But, having said that, my God was it testing.”

Within that questionnaire, Lesley listed her likes as “dinner parties, country-house weekends, Victorian literature, Michelin-starred restaurants and fish and chips.” Her dislikes included music, people without ambition and “doing anything domestic”. By her own admission, she has a personal trainer and a cook. But, hang on a mo, someone obviously is domesticated in this house, with its air of cosiness and welcome.

“Coffee?” asks her rather charming architect husband, David, bang on cue, bustling kindly and self-effacingly in.
The more you see, the more you wonder why on earth this couple chose to put themselves on the line like this. Unlike the youngsters who volunteer, these two look as if they don’t want the fame and don’t need the money.