Yes, I am in the same boat as you guys. It is a constant, never ceasing onslaught of ideas, thoughts, problems and their solutions, theories, etc. Plus, there is always music playing in the "background" of my mind. The music never stops! It's like a radio that won't turn off.
Also, I think visually, as in Temple Grandin style. So the thoughts and internal dialogue are represented by movies, models or pictures going super fast.
Would everyone like to know what goes on in the NT brain during all that "free time"? Well here's a short story about that...
My NT fiancee realized very early on in our relationship that I don't think like the regular Joe. There was one instance where I worked out the best solution to a problem he was having (the logistics of him moving across town) in about 20 seconds and he asked, incredulous, "How do you think so fast?!"
I explained to him that I can play out all the most probable scenarios very quickly in my mind, and make a fast decision as to which is the best. He didn't get it. So I asked, "Well then how does your brain work?"
He explained that if he had an idea, the idea would just be a sort of thought in his head, and he would have to work out the details one step at a time. I asked, "Are there any thoughts like pictures, or movies, or scenarios where you see people doing things?" He said no, that it was more of just a thought (whatever that means!). So I asked, "Well then what's in your head when you don't have a 'thought'?"
He said, "Nothing much, really." Nothing?! Yes, apparently, in the average NT mind, there's just existence. Quiet. He did elaborate a little, that whatever he's looking at or doing at the moment might elicit a memory or some 'thought', but only for a short moment. Otherwise his mind just...exists.
I can't imagine being like that. I've always thought my brain was a curse that I couldn't shut off. But I think I'd rather have all the knowledge, ideas, and creativity that comes with being Aspie!