Confidence is the key to success, with a little bit of luck thrown into the mix. But confidence can be a chicken and egg thing. Once you achieve success you feel confident as a result of that success. How can you feel that same confidence before you have experienced success?
Only optimists play poker. Why would a pessimist even bother? There would be no point in even trying. After all, poker is a game that's all about winning. Gambling is all about winning. And a serious gambler (or an amateur who takes the game seriously) is always on the lookout for a new technique which could stack the odds in their favor.
Now I had a funny experience a few weeks back. I'm a hypnotherapist and I sell a lot of mp3 downloads from my website. I had an e-mail from a would-be customer asking why I sold cds for winning poker and not for winning at the dog races....Interesting concept.