It isn't what you have or who you are or where you are or what you are doing that makes you happy or unhappy. It is what you think about.
Dale Harbison Carnegie (November 24, 1888 – November 1, 1955) was an American writer and lecturer and the developer of famous courses in self-improvement, salesmanship, corporate training, public speaking, and interpersonal skills. One of the core ideas in his books is that it is possible to change other people's behavior by changing one's behavior toward them.
Enjoy the best Dale Carnegie picture quotes.
Read more about Dale Carnegie on Wikipedia.