I dont think I have ever met anyone who comes from being quiet (naturally) to being a sociable person and regretting it. He wont be saying this isnt me (sociable) and let me revert to being quiet because that is the "real" me.

I sometimes wonder if changing one's behaviour is a matter of decision. E.g. If you are lazy by nature, I wonder if you can just decide that enough is enough and I want to stop being lazy and indiscipline.