Doesn't sound like flight of ideas, which I hope sets your mind at ease. As I understand and have experienced them, they are rapid fire and often disconnected. About 10 seconds later, I can't remember the previous thought, though it was "brillant" at the time.

I agree with pachyderm... a lot, if not all, people have conversations in their head. It can be a way to figure out how you feel about something so you are more prepared to articulate it.

Don't know if this is the case for you, but I think (and seem to recall reading) that introverts tend to do this more often due to the need for alone time to re-charge, process and even rehearse. Conversations are on-the-spot events. I (introvert) needed to learn to defer answering, (even if only for a short time) so as not to agree to things I didn't even want to do(!) if they had even been given even the slightest time for reflection. But mostly I need to prepare for the different ways a conversation might go. Hope that's not too off-track.

Long/short: I wouldn't worry about it.