This finally occurred to me the other day. NTs can just have a conversation without putting in to much effort but for us it requires concentration. Casual small talk becomes a chore so we get tired off it and try to get out of the conversation. This isn’t something NTs can understand since they don’t have to put thought into talking and acting “normal.”
The possible exception to this is when Autistic people talk about special interests. This creates dopamine in the brain so we basically become high.
For me it was my uncle acting shocked that none of my cousins knew some really obscure historical figure in US history. He then talked for a hour or two.
“Jeez dad, nobody cares about this George Washerman or whatever.”