In school, I used to be very shy to the point that I would almost never initiate a conversation with anyone who wasn't my friend. It was awkward but the shyness became my identity and I later became afraid to break that social image, even though it was mostly negative.
I felt like everyone else was part of one cohesive hivemind and that they all understood and could relate to each other - I felt different; I didn't feel like I was a part of this hivemind and I couldn't connect with others in that way.
Later in college, I met more like-minded people and one of my friends used to say that the best way to overcome shyness is to intentionally try to humiliate yourself. I tied that out for myself and it helped a lot.
I became a lot less shy over a few years but I still had the problem that I tried to please others. Also, I still didn't feel like I was part of the hivemind. I couldn't connect and interact with others with the same ease as they connected and interacted with each other.
10 years after finishing university, I had some very difficult career experiences. I encountered some really nasty people. Realizing how evil some people are helped me to get rid of my people-pleasing tendencies.
Also, for some reason, nowadays it seems to have become impossible for me to humiliate myself by saying whatever comes to my mind. At work, I could share some really outlandish theories and ideas and it only made my colleagues treat me better and respect me more;
this created a positive reinforcement which made me appear extroverted.
My personality did a full 180. I feel zero anxiety when talking to other people now, including large groups.
I no longer have negative thoughts about myself like "I'm so dumb for having said that, it was so awkward" now I only judge other people, never myself. My self-confidence is very high now and I embrace any awkwardness.
My problem now is that people are sometimes intimidated by me because I always say what I think and I never follow any social convention or fear awkwardness.