I think this is really why you don't have to worry about competitors. If your idea is good enough, everyone will think you are crazy/naive. If your idea is simply decent, you'll never pick it anyway (because it's not exciting enough to you) and it will end up getting done by some existing company. Either way whatever you actually choose to work on will be unique until it's proven, by which point no competitor is catching you anyway.
It's not just about feeling. If Google had tanked, you would be more justified (in a statistical sense) to think that you're smart and to engage into more financial transaction.