I'm not going to thoroughly review Mind Wide Open by Steven Johnson; you can read about it on Amazon. Better yet, if you want to know how your own brain affects you and acquire greater self-understanding, buy it and read it.
Anyway, there are two things I like about this book even though I'm only 1/4 way through it. First, he starts out with his personal experience of his own brain as he cracks a joke while wired up to a neurofeedback machine. Perhaps out of boredom, perhaps out of habit of his own personality, Johnson was able to see how his humor gave him a rush, all the more powerful because he could see it being charted out on a graph.
And in that instant he acquires deep self knowledge about his drug of choice: humor, and how he uses it - often inappropriately - whenever bored, just to get that rush.