Whenever I start a new book, I think, 'This is the most interesting subject of all time. It's sad, I'll never enjoy writing another book as much as I enjoy this one.' Every time, I'm convinced. And then I change my mind when I start the next book.
Like most people, I have several pet subjects - that may or may not be interesting to other people. Don't get me started on happiness, or habits, or children's literature, or Winston Churchill, unless you really want to talk about it.
It was my interest in happiness that led me to the subject of habits, and of course, the study of habits is really the study of happiness. Habits are the invisible architecture of everyday life, and a significant element of happiness.
Happiness is hard because it's very subjective. I know the people that seem happiest to me, but whether they are actually - what they're really like inside is really hard to say.