I think out loud, too. It is so bad that by the time I am finished mulling something over in my mind, when I go to tell my husband or my daughter they invariably will say, "you already told me that". At this point, I have to explain to them that what they have heard before may or may not be the complete thought because I was still "thinking" about it..... they have to listen to the latest version of the thought! It's sort of like Windows Updates for my brain!! HEHEHEHEHEHEHE.....
I also quote movie lines..... I will hear something that makes me think of a line from a movie and I will say the line I am thinking (or part of it). Sometimes I will even ask people around me if they have seen "such and such" movie and then I will go on to explain why I have blabbed out a line. It makes me seem eccentric rather than totally nuts!! Once in a while, I will find someone who has seen the movie and they will usually laugh and want to talk about the scene.... for a shabby little moment (I'll take what I can get.... hehehehhee).
The majority of the time, however.... the trigger for the line or quote is a single word that is totally unrelated to the line or quote that I want to blurt out. As a result, I have to filter where I am and what I am doing..... if I am alone or with my daughter.... I will just blurt out the nonsense. If I am in public, around my husband or other friends.... I try really hard to keep it a "thought only". I think this is one of those things that makes dealing with people at large exhausting. I have to filter a lot of these weird comments, withhold swaying, tapping, rubbing, etc., interpret facial expressions, body language, tones of voice, etc. and THEN I have to filter it all, process it and respond. After a few hours of dealing with another person, I feel about the same as if I had been taking some sort of test for a few hours. Tired and ready for a break! I think that to be able to really enjoy the company of someone else, I have to be able to at least make random comments or tap my fingers or something along those lines while I do it. People who know me well know that I am prone to tangential thoughts and seem to cope reasonably well. I don't feel tired after talking to these people like I do when I have to talk to someone who requires more "filtering".