I love the chapter in the Oxford handbook of human motivation by Abigail Scholer and E. Tory Higgins (2012): 'Too much of a good thing? Trade-offs in promotion and prevention focus'. Basically, it says that people vary in terms of how much they are 'promotion-focused' (trying to make good things happen), or 'prevention-focused' (trying to stop bad things from happening). But the really interesting point is that if you are a very prevention focused person--someone who's always trying to stop catastrophes from happening--then you can't expect to experience too much happiness: after all, that's not what you're aiming for. At best, what you're going to experience is calm and relief. And the same thing holds for people with a natural tendency towards promotion: if you spend your life trying to get new experiences (that's me), then you can't complain if you don't have much calm or respite in your life (that's me too). What's the solution? Scholer and Higgins suggest that it may be best to have a balance of prevention and promotion focus, so that you can make the most of whatever situation and circumstances you encounter. So the first thing to ask yourself is whether you're a promotion or a prevention kind of person. Then think about whether you want to bring a bit more of the other one into your life.
If you're 'prevention focused', don't expect to be happy (and don't expect to be calm if you're focused on promotion)