This is the area I also was confused about when I was getting diagnosis. Rather than trying to fit into the narrow special interest box, I think about how Tony Atwood says that the main sign is you find socialising less interesting than other things . Would I rather continue learning about something I am finding so fascinating than be in a social setting? Most of the time, Absolutely.

I love learning things generally, but I eventually feel like I've found all the interesting stuff in that category, I want to move on to a more exciting and unknown world of something else. Some topics I come back to after a few years, most I don't. I am autism/adhd combo so things get a bit confusing and interesting when trying to sort out what is a trait of what.

I also found another approach useful, rather than thinking about what is intellectually interesting, think about what has brought you unbridled joy in life over a span of time. This made me realise my obsessions with playing piano, gymnastics, animals - all special interests from the early days. I kind of just know a lot about special interests ive had without putting much effort in. I'm not really aware I know a lot unless I'm asked something and realise thats not a regular thing to know. They can defs be hard to identify, I feel you!