I came upon this thread whilst googling to figure out why I've had a very awful word stuck in my head all day today. I first read and comprehended the word today and it has been continuously popping into my head, which has been extremely frustrating as I simply don't want it in my head. When I do think of it, it's not related to the topic either of a conversation I'm having with someone else or relevant to my train of thought. (Sorry for the poor grammatical structure, I just finished writing too many English assignments and I've sort of given up on coherence for the night.) I found that I have experienced almost all of the occurrences detailed in all of these posts though I have not been diagnosed with or suspected of having any form of Autism, though I do have a form of epilepsy. Upon continued "research" of the phenomena in my quest to end my suffering of the recurring prominence of the word in my mind, I stumbled upon a similar website for epileptics, with a very similar question and many responses that said almost the same thing. I suppose this is less of an explanation for why you may be experiencing this, and honestly may even make the cause less clear, but I thought it was interesting and worth mentioning.