I have certain loops of thoughts, distinct from anxiety, that replay themselves pretty quickly in my mind. Some of these are thoughts that I like and enjoy repeating, and so it's almost like a form of stimming. Others seem like things that I'm still trying to get right in some way and can't let go of. The two times when this happens most often are 1) when I'm in a loud, crowded situation and I'm "zoning out" in my little bubble, or 2) on the other extreme, when things are quiet and boring and I have to entertain myself.
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"And there are days when I would be away . . . Oh, wherever men of my sort used to go, long ago. Wandering on paths that other men have not seen. Behind the sky. On the other side of the rain." -Jonathan Strange and Mr Norrell