What's the best way to be happy?

I think you are correct for the most part. I believe that when we make others happy, not just those that are near and dear to use, it makes us happier as well. When you make someone else smile, or lighten their load, or just feel better about themselves, you are giving something precious to them. That in turn makes you feel better about yourself. Unselfish giving is one of the best ways to make the world a brighter place.