Good ideas are like Nike sports shoes. They may facilitate success for an athlete who possesses them, but on their own they are nothing but an overpriced pair of sneakers. Sports shoes don’t win races. Athletes do.
Bet on the jockey, not the horse.
My professor used to drill this saying into us in my Intro to Entrepreneurship class 2 years ago. I still use that quote most when giving advice to other students who have an idea but are hesitant to share it.
My freshmen year in college, I met two students who had just received VC funding, and they told me one tip that had helped them most: they shared their idea with anybody who would listen, because they never knew how somebody might be able to help them along.
If you truly have a good idea, somebody else is working on it too. You might as well talk about it and get all the help you can.