Some comments:
1) Intellectuals are annoying. As the saying goes: "intellectuals are people who are educated beyond their intelligence". From your description, you appear to be a people person. They're much more interesting. You don't need to become someone else.
2) Stop worrying about what others may or may not think about you. If you don't know something, simply state that you don't know it. Don't feel guilty about it. It's not a confession, just a fact. No one knows everything (except intellectuals, who at least believe they do). Ask the other person to explain it. If they won't, then they either don't understand it themselves, or they're just nasty. Don't doubt yourself. Be confident when you speak up. If you're wrong, someone will point it out and you'll have learned something. There's nothing wrong with having the mindset of a "beginner", and beginners are allowed to mess up. In fact, once you get rid of that mindset, you become complacent and nasty yourself.
3) You don't need to go to school to learn stuff. Read books, check out Wikipedia (lots of stuff to learn there), browse the net. School just gets you a certificate, and you don't need that, because you no longer care about how others judge you.
4) Take it easy on yourself. You're already pretty cool. Feel good about your accomplishments, forget about your failures. In fact, from now on failure is no longer a bad thing. Put yourself in a perpetual state of learning -- now when you're wrong that just means you learned something. So it's good to be wrong!
Hope it helps!
