My current understanding is that thinking, at least at a "high level", is a very social process. Which is why rubber duck debugging exists, why people imagine talking to someone when they want to think through really hard problems, why most ancient philosophy was written as dialogue, and why you posted this thread here. Apparently Descartes was wrong and it is not "I think, therefore I am", but "there are others, therefore I think".
But I have social anxiety too.