Nothing in the world can make you happy; everything in the world can encourage you to be happy….
The world cannot take away your right to happiness or sadness. It may often appear to be trying very hard to take this choice away, but truly it cannot. Events in life can so conspire that you may lose sight of this choice, but never is the choice destroyed. In truth, the decision to be happy or sad always rests with you, whether you can see it or not. It’s when you temporarily lose sight of this choice that you must ask for help.
— Robert Holden, PhD, Happiness Now! p. 48, 51