Confidence and Experience

I took a ceramics class in my second(?) year of college. I think one of the hardest parts of the class for me was going into the ceramics lab to work on projects when I was not specifically scheduled to be there. I remember walking up to the doors but because they were closed o this particular occasion and generally they were propped open I couldn't bring myself to push them open and go in.
Now, looking back I can totally understand my hesitation but I don't think I would run away anymore (I hope).
This week my sister and I were talking about self-confidence and how to develop it yourself or encourage it in others. The conclusion we came to is that new experiences tend to bring more confidence. There could be two reasons for this. One, if I work long enough on the same thing I learn more of the in and outs of whatever it is (whether it is learning Microsoft Excel or playing frisbee). Thus, I gain confidence in that specific area because I am more comfortable with it.
That would help with confidence in a specific area but if I want to gain more confidence in general I think the key is varied experiences because that way I have more things I can relate to and more experience in trying new things itself. While trying lots of different things perhaps instead of learning the ins and outs of a particular skill I learn the ins and outs of being uncomfortable and what types of things make me uncomfortable and what type of things I can do to alleviate it while still participating.
I'm by no means amazing at this but it is certainly something to think about.