"We blow things out of proportion," he explains. "When people are dealing with the big stuff in life - death, earthquake, financial crisis - they find an inner strength. But they freak out over the smallest things. The big things are few and far between, but the little things drive us bonkers. It's very exhausting and it takes the joy out of life."
Carlson ran a stress management centre for 10 years before he became an author, and, he believes, a good proportion of stress is self-inflicted. "If you are burgled by someone with a gun or your child has a seizure - that's real stress. But many people treat everyday things like front page news; they take a little drama and blow it out of proportion. The first step to controlling it is to admit that you do some of it yourself, that some of it is under your control."
The human condition, he reminds us, is not a bowl of cherries. "We have come to believe, especially in industrialised Western nations where we are very privileged, that our lives should be perfect. We feel like we shouldn't have to deal with traffic jams or flat tyres or people who are rude to us." The truth, he says, is that such hiccups are part of life. "Life's not perfect - but it's not an emergency either. We come closer to happiness if we embrace and accept that."
And this is the basis of his philosophy: embracing, accepting, turning the other cheek on an epic scale. His book, which has sold three million copies in the US and reached the top of the New York Times bestseller list, contains tips for achieving harmony with life's pinpricks. Number one is "Don't sweat the small stuff"; number 25 is "Smile at strangers, look into their eyes and say hello"; number 62, "Do one thing at a time"; number 74, "Do a favour and don't ask for, or expect, one in return", through to number 100 - "Live this day as if it were your last. It might be!"
The flaw, of course, is that while you are calm, controlled and at peace with the universe, the traffic warden who is booking your car or the boss who is setting impossible deadlines may not be in tune with your new vibrations. But, says Carlson, "As you become more peaceful, you simply aren't bothered; you get a great feeling of satisfaction from being peaceful. The things that used to bug me have no effect any more. And when you are calm, you will see changes in the people around you - not because you are changing them, but because you are setting a good example."
And, he adds, this is also a recipe for success at work. "People overestimate how much being in a hurry is important for success. A calm mind is more powerful. When you are calm you make less mistakes and you don't repeat them. You see solutions much more easily than when you are frantic." He is so convinced of this that later this year, he will be publishing another volume of 100 hints, this one entitled Don't Worry, Make Money: Spiritual And Practical Ways To Create Abundance and More Fun In Your Life.
And he practises what he preaches. He has given up his stress management clinic, because it was all getting too, erm, stressful. "When the book became a success, there were so many demands on my time and I didn't want to be frantic," he admits. "I can't be in two places at once any more than the next person can."