Well, having a large penis makes me happy (keeping it LPSG-relevant). Other than that, it's about accepting what life gives us. I like meditation as a way to develop the capacity for acceptance. You could also check out happier.com - they have some good stuff there. But keep in mind that real happiness comes from within, when you are at peace with life's circumstances. Happiness based on how well things are working out in life is a fragile thing, and also less satisfying. But the good news is that it's a lot easier to work on your own attitude than to fix everything that goes wrong with your life. Best of luck!