Mental accounting is considered a classic logical fallacy. People treat money differently depending on where it's coming from, so if you find money on the street, you treat it more casually and spend it more quickly and more frivolously than money you've actually earned. The parking-ticket example illustrates how you can turn this logical fallacy to your advantage. You're deliberately tricking yourself—for the sake of your own peace of mind.

Next time you hear that an apparently perfect marriage between two perfectly well-matched partners is on the rocks, don't be too surprised. It's a clear case of set-up overestima-tion. Frankly, anyone who's spent more than five minutes in a relationship should already know that without ongoing fine-tuning and repairs, it doesn't work. All partnerships have to be consistently nurtured. The most common misunderstanding I encounter is that the good life is a stable state or condi-tion. Wrong. The good life is only achieved through constant readjustment.

There's no such thing as the ideal training. There's no perfect business strategy, no optimal stock portfolio, no one right job. They're all myths. The truth is that you begin with one set-up and then constantly adjust it. The more complicated the world becomes, the less important your starting point is. So don't invest all your resources into the perfect set-up—at work or in your personal life. Instead, practice the art of correction by revising the things that aren't quite working—swiftly and without feeling guilty.

We overestimate the role of the set-up and systematically underestimate the role of correction. Our lives work like a plane or a car. We'd rather they didn't—that they ran according to plan, foreseeable and undisturbed. Then we'd only have to focus on the set-up, the optimal starting point. We'd arrange things perfectly at the beginning— education, career, love life, family—and reach our goals as planned. Of course it doesn't work like that. Our lives are exposed to constant turbulence, and we spend much of our time battling crosswinds.

Do you hate queuing at the supermarket till, waiting at the dentist's, and sitting in traffic jams on the motorway? Your blood pressure reaches 150 in seconds, and you start frantically releasing stress hormones. But instead of getting upset, consider the following: without this unnecessary agitation eating away at your body and soul, you'd live a whole year longer. That extra year would more than make up for all the time you spent in queues. The upshot? You can't nullify the loss of time and money, but you can reinterpret it. Open your box of mental accounting tricks and see for yourself: the more practiced you are at dodging fallacies, the more fun it is to occasionally commit one on purpose. Remember, it's for your own good