Glad you wrote this. I am going on 15 years of being self taught and constantly trying to learn more. I've built a whole lot in that time, but nothing has ever seen the light of day and I've never* done anything with it professionally. After much hesitation, I recently pulled the trigger and signed up for an upcoming Startup Weekend event. The hesitation comes from the thought that I will be light-years behind everyone else there, and basically won't be able to contribute at their level. This give me some confidence that I won't be a total drag on some team.

* OK not entirely true - I'm in finance, and I do quite a bit with Excel VBA - but I don't really count that as real programming, although it has served me well in my field