Remember the five simple rules to be happy:
1. Free your heart from hatred – Forgive.
2. Free your mind from worries – Most never happen.
3. Live simply and appreciate what you have.
4. Give more.
5. Expect less
I think that it was Dr Victor Frankl who recognised after living in a concentration camp that happiness when pursued as an end in itself was a futile goal. He recognised that even when people lived in the most attrocious conditions that there could still be a measure of joy in their lives.