If you have a great idea, assume that 10 other people are working on it. I've never met a paranoid entrepreneur who was successful. The successful ones share their ideas, share their equity, share their dreams, and bare their souls. Fifth, pursue entrepreneurship for the right reasons. This is the hardest lesson of all to learn.
Happiness is temporary and fleeting.
It should not be the goal of entrepreneurship. Joy is the right goal. But joy, by contrast, is unpredictable. It comes from pursuing interests and passions that do not ''obviously'' result in happiness. It comes from building a great team, from family, from friends and from inexpensive if not free things.