What are you responsible for in your own happiness?
What in your own happiness are you responsible for?
What happiness is your own responsibility?
What responsibility is your own happiness?
What responsibility?
What happiness?
What you is responsible?
What you is happy?
Your own happiness.
Other's happiness.
Your own responsibilities.
Other's responsibilities.

http://www.straightdope.com/classics/a980814a.html

I would think too about my responsibilities to be happy? If you have a choice between half empty and half full, choosing the half full doesn't change what is there but certainly changes how you perceive it? Actively looking for "happiness" or the "positive" instead of expecting it to show up probably could bear some inspection?

Why am I getting a headache? Do I think too much?