CHATTING to mind reader Doug Segal offers a little indicator that he may be slightly out of his mind.
It transpires that before he took to playing around with other people's heads, the acclaimed performer was a high-flyer with an advertising agency.
Doug, who layers his mind-reading act with comedy was making "stupid money" and living the high life.
But he gave it all up to practice auto-suggestion and live the perilous life of a performer, working for less than the minimum wage.
Is he bonkers?
"I was a director on the board of a major UK ad agency," he recalls of his early career.
"I had worked my way up and was very successful."
He adds, grinning; "Mine is a rags to riches to rags story."
Yet, success implies enjoyment?
"That's not always the case," says the mind reader, who's set to bring his mind reading show to Glasgow at the end of the month.
"Advertising wasn't my natural world. I was in bands as a young man, we supported the likes of Phil Lynott, Mr Big and Aswad, on tour and I had an Equity card in my late teens.
"But then I had a son really young so I had to become a grown-up. I had to get a real job. So I sold out - then bought back in."
Doug had studied psychology at uni, which helped him in his career in advertising; he understood how subliminal influences worked. "And the power of cheating and lying," he adds, laughing.
However, the showbiz dream hadn't been abandoned entirely. Doug studied mind reading.
He began doing little party pieces, tricks with people at lunchtimes, and after seeing one of these pop-up performances, one of the ad agency's major clients bullied him into doing a show.
"To be honest, I only did it out of fear of losing a client. So I booked two weeks at Baron's Court Theatre and I advertised it. I stuffed it with people I know and they told their friends. I knew how to advertise.
"And it worked. One person who came was a BBC producer and that launched me. Then I was picked up by Dutch television show Jensen, oddly enough, and I ended up appearing six times. Before I knew it I was moderately famous in Holland."
Doug's son was now older, and he reckoned the time was right to make the leap into entertainment full-time.
He said: "I had been ridiculously overpaid in advertising. When I split from my wife I had bought a flat in London, which I was able to sell at the height of the property boom and pay off the mortgage.
"I then bought a little house in the country and set about creating a new career."
But he didn't want to simply follow in Derren Brown's footsteps.
He said: "I was always being compared to Derren Brown, but Derren is very serious. And I knew I could be funny.
"Yet, I knew I had to get better at being funny, so what I did was make stand-up my hobby and join the comedy club circuit.
"I did spots for stage time, and worked my way up. But then I gave up stand-up because it had been all about making the mind reading act funnier."
The mind games/comedy routine worked. In 2012, Doug's Edinburgh Festival Show How To Read Minds And Influence People won two awards.
The entertainer was described by one critic 'Imagine if Derren Brown was funny . . .' which is an incredible accolade, given Brown's popularity.
Doug's follow up I Can Make You A Mentalist received huge critical acclaim from the likes of critic Kate Copstick, who wrote 'Doug Segal turned me into a mentalist. It was the most extraordinary experience of my life.'
"This new show is blend of mind reading, stand-up and sketch comedy," he offers. "And what I do is strip back the secret.
"I reveal how it's done by having a member of the audience read the mind of other members of the audience.
"I give them a written technique, a sequence of things to do."
Doug also has the audience members performing sketches in which they become Victorian detectives to read others' minds.
"We film it all and replay a video, again revealing how it all works."
Does he worry about killing the illusion?
"Not at all," he says. "And it doesn't take away from the show."
Doug demonstrates his skills, asking me to move four objects around on my desk continuously and randomly, in any order I choose.
EXCEPT he's doing the choosing having implanted suggestions in my head, so that he knows exactly where each object will end up.
It's very, very clever. But does he ever use his powers of persuasion for bad?
"With great power comes great responsibility," he says, grinning. "And you have to remember, I can only control the environment in a small area."
What about when Derren Brown convinces a bookie to pay out on a slip which contains a loser? Can Doug Segal convince people to give him money?
"You've got to be aware that Derren is featured on a television show," he says, diplomatically. "Three minutes of great TV can take three hours to make."
In trying to plant thoughts in so many heads, and 'read' the answers of so many people at the one time, does his brain hurt?
"Yes, there's so much to remember," he admits.
"And there's a moment before the end of the show you think it needs a miracle to pull if off.
"But every time I end up with a result I'm delirious."
l Doug Segal, Tron Theatre, March 21.