The world cannot make you happy. Only you can do that, and it is easier than you think. You can be happy just by deciding to be. Though it sounds shallow and simplistic, such an approach to life is actually quite sophisticated and effective.
To make the best of what you are, requires that you fully appreciate what you have. What better way to do that than to be happy with yourself and your life?
Is it possible to be happy when things are not going your way, or even when a terrible tragedy strikes your life? Yes. The events and circumstances around you do not define you. Feeling sadness is natural, healthy and unavoidable. Yet that sadness, though it may be intense, does not have to define you. You can be disappointed with external events, and happy with yourself, all at the same time. And in your happiness there is potent energy with which you can overcome the sadness and disappointments.
Be happy -- not because you are too foolish to know any better, but because you are smart enough to know it works. Be happy, and be your best.