"Folks are usually about as happy as they make their minds up to be."
I could not agree more with this statement. Happiness is a choice.
Everyday you have the opportunity to make it either a good day or a bad day and it's your attitude that makes the difference. If something goes wrong, you can either find a silver lining or act like a victim, but how you react makes all the difference. If you make up your mind to be happy at the beginning of the day, you will find that silver linings are much easier to spot when obstacles pop up.
You are the only person who is responsible for your feelings. No one can make you happy or sad but you. If you make up your mind to be happy, you will find it much easier to stay that way.