Most psychologists assume that the extent to which happiness is developable is limited. They think there is a so-called set point. This is a biologically determined range within which your happiness would move. Many laypeople also seem reluctant in the achievability or developability of happiness. Brad Pitt, the movie star once remarked in response to the question whether he was happy: “I don't believe in happiness.” Now, the thinking about happiness seems to shift among experts. Ed Diener, a well-known happiness expert says: “Set-point is not destiny. In fact, happiness probably is really about work and striving. Happiness is the process, not the place. So many of us think that when we get everything just right, and obtain certain goals and circumstances, everything will be in place and we will be happy…. But once we get everything in place, we still need new goals and activities. The Princess could not just stop when she got the Prince.” The article Do you have what it takes to lead a happier life? describes a very simple approach that seems to have helped many people to increase their happiness: think every night about three good things that have happened that day and analyze why they have happened.” I have talked several times about the growth mindset on this site. Then, the question was whether intelligence is developable. Is the growth mindset also applicable to happiness? I don't know. The exercise might help. It seems worth a try.