You can't be afraid to fail. It's the only way you succeed - you're not gonna succeed all the time, and I know that.
There are lots of things I could have done for the money, but I've made a great living doing the things I want to do.
Absolute certainty is not something I strive for anymore. I've learned the hard way that destiny usually looks upon our most strident convictions with amusement, or perhaps even pity.