The secret is not to give up hope. It's very hard not to because if you're really doing something worthwhile I think you will be pushed to the brink of hopelessness before you come through the other side.
I just try to try to keep an attitude that I don't know what I'm doing. Not to the point where I'm beating myself up but I just go in thinking that I have a lot to learn. And I hope I still have that attitude 30 years from now.