Most shy people wish they were more confident, because shyness is ultimately a symptom of you being uncomfortable with who you are. You judge yourself based on other people's standards and spend too much time in your own head, thinking of how best to act and react in any given situation. This is nothing more than a bad habit, and it's the sort of thing you can break with regular practice.
I was a loud, confident kid when I was young. Then I transferred schools after 6th grade and was one of a few people who didn't know anybody. After a few failed attempts to make friends, I became shy. It was easier to just be quiet and avoid everyone than risk rejection. That shyness took only a few weeks to develop and it stuck with me for years. Author James Victore believes it's really nothing more than a bad habit:
"Most of us are so afraid of failing that we don't even risk it. And what's worse, risk and rejection become something to avoid at all costs. A habit is formed. We close doors that may lead to opportunities and stop putting ourselves out there for other people to respond to. This fear of rejection is normal. Everyone shies away and has moments, or extended moments, of self-doubt. But the fear is also a test, it means you are onto something and you should pay attention to it and not shy away."
That fear is a good way to detect opportunities, but it can be easy to think we're too shy to make good use of them and find an excuse to avoid them. Like with any bad habit, you're not going to turn your diffidence into confidence in a couple of hours. Breaking a bad habit just involves forming a better one in its place, so make an effort every day to do something you'd otherwise avoid because you feel shy. Try simple things, and then when those big opportunities come along and strike you with fear you won't worry so much about the results. If you practice thinking just the right amount, rather than analyzing every possible outcome, that'll be your new habit. Just get outside of your head and be present in the moment every day. You'll have far less trouble next time you need to summon some confidence because you won't be thinking about it.
LifeHacker.com