Sometimes while I'm doing something mundane (such as watching TV), my mind turns into some sort of blank fog and I start getting extremely concentrated on my thoughts. The problem is that my thoughts become only about what's going on such as what I'm hearing and seeing, and I can't piece things together like I normally would (i.e. I hear dialogue from the TV, but I have to make an effort to comprehend what I heard or else it just sounds like a stream of words). I also get an urge to do something spontaneous that would get my heart racing, such as jumping or running around. This whole thing lasts for about 5 minutes. Can anybody explain what is going on or what causes this? The reason why I am concerned is because it gets frustrating to not be able to think freely while watching a movie or taking notes on a lecture.