Autistic obsessions tend to clash with the tendency of those with typical wiring to crave variety or novelty. It's actually a cornerstone of neurotypical psychology and one of the main driving forces behind consumerism. I think it's the reason why my NT family reacts the way they do to my obsessions - saying that it's useless, irritating, etc. I've been scolded for wasting time on obsessions when I could be devoting myself to more productive hobbies or been limited to "one fact a day" when I over-shared. I don't think that it's anything to hold against them. They view my fixations the same way that I view most small talk in conversations - boring, pointless, annoying. I can respect our differences, I just have to find other outlets. I've often kept notebooks and journals, or even written novels, about my special interests. These give me a place to obsess - and pouring out all of that information someplace is often an important part of a fixation. I've found that if I commit those rantings to paper, I feel less of a need to pester the people around me. You could try creating a blog or starting a diary for that purpose.
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I have not the kind affections of a pigeon. - Ralph Waldo Emerson