I was extremely shy and timid most of my life, and it wasn't easy. After I went through a bout of depression a few years ago I stopped caring what people thought so much, and even though I am pretty much over that now, still I am very rarely nervous when in public, or at least, not in the same way as before. I am sure I would be a bit nervous if I had to get up in front of a crowd and speak, though I am terrible at talking the way it is, not really my gift.
But really, everyone I meet usually reminds me of someone who I know already, so that makes it easier, plus I like to imagine how their life is and know that everyone has family like I do too. Now I think I usually feel very relaxed around most people.