I'll be giving a talk about roughly this subject soon, but here's one to mull over:
Snap out of it! That daydream you're having about eloping to the Bahamas with Johnny Depp or Angelina Jolie is leaching away your happiness. In a new global study, researchers used iPhones to gauge the mental state of more than 2000 volunteers several times a day—even when they were having sex. The results indicate that, if you want to stay cheerful, you're better off focusing on the present, no matter how unpleasant it is.