When they assume I'll know all about their autistic children, and be able to interpret all their behavior for them, and understand everything they ever do. Even though I've never met the kid. I mean yeah sometimes I'll know something of use, just because of knowing about autism, and sometimes I'll know that their predictions aren't absolute (like when they say "I know my child will never ever..." and the child is like... three years old, give me a break). But I'm not a Universal Translator of Autistic Behavior.
One really creepy one referred to me once in that regard as a "Rosetta stone". No... just... no.
When they automatically assume based on some superficial trait, that I'll either be exactly the same as, or totally different than, some other person.
When they try to make me seem like an exception among autistic people, for (sometimes) being able to do things that... most autistic people can do.
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"In my world it's a place of patterns and feel. In my world it's a haven for what is real. It's my world, nobody can steal it, but people like me, we live in the shadows." -Donna Williams