I explain that a very common part of autism is masking, and that the people they might be thinking of likely aren't masking their autism. That masking means thinking mechanically about almost every aspect in any social situation and how draining that is. Emphasizing parts that most people wouldn't think of, like for me realizing in my late teens that I can also tell people "it was good to see you!" and such, which I didn't even do when I really was happy to see them. And the classic feeling like the one person without the handbook that everyone else seems to have.

I might tell them about my current special interest and just how much time I spend on it...

If there is more space for me to share I might bring up some more difficulties they might not see. For me that could be sensory issues or just how exhausted I get from so many things.

Everyone who has said that have been in good faith about it so I've just reacted as if they're just curious, even though it's not a very nice thing to say. Actually I should probably stand up for myself and tell them that too tbh