This is a novel about a psychiatrist who begins to wonder why so many of his patients are well-off, healthy, and have very few substantial problems, yet are unhappy. He wonders what is the secret to happiness and decides to go on a quest to find out. He travels around the world, to places where he has friends, and makes an effort to be attentive and to write down his observations about what makes people happy or unhappy.
The novel is written as a kind of children’s story (though there is plenty of sex and violence that probably make it unsuitable for actual children). I found it to be a real delight to read, while still having useful and science-backed content. His travels to China, Africa, and the US are interesting in themselves, with a couple hair-raising adventures along the way, and the Hector character is really likable - he tries to be as attentive and understanding as possible with everyone he meets, including some very unsavory people.
The word ‘attentive’ appears many times in the novel. Hector sees attentiveness as an important characteristic for the kind of psychiatry that he does, but also for any kind of human relationships. He is very impressed, for example, by the attentiveness of a Buddhist monk in China as Hector is explaining his quest. And, naturally, the characteristics that give rise to attentiveness are also ones which contribute to happiness (caring about the happiness of others).