Authors:

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 Carnegie (2010). “How To Win Friends and Influence People”, p.67, Simon and Schuster
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.