Middle Son is profoundly autistic. He doesn't speak, but he laughs and hums and grunts. He loves to jump and run and spin. Sometimes I bring him along to Oldest Son's Boy Scout troop meetings.
I can ALWAYS tell who knows about his autism and who doesn't. As he is humming or giggling or spinning or jumping, the people who know look at him warmly and affectionately. The ones who don't glare and scowl.
Via liberal japonicus I saw a story in the The Guardian about Glenn Campbell, who now has Alzheimer's. There was a quote from his daughter:
"When he messed up, people were coming up to me after shows and saying 'Is your dad drunk or is he using again?' It upset me. Now this is out they're just going to be supporting and loving him rather than angry that they paid to see him."
Different condition, but the same result.