I feel similarly. I often find that I run into people who are eager to have a face-to-face debate about something, and who come up with opinions and rationalizations that sometimes end up being dubious. But I feel a strong desire to hear them out and I generally have a hard time piecing together what makes an argument fallacious until I have time to analyze it more deeply, so I generally just take whatever they've sa…
Like you, I also tried to be a quick thinker/talker in situations and disliked who I was becoming. But nowadays I've learned to be ok with it... because I found value in trying to be charismatic so I can rally people around my cause.
Put me in a completely new situation and I'll revert back to listening and thinking slowly. But talk to me about something I'm really passionate about, and I'll be a quick talker. It feels like a flow state.