Thanks for so accurately describing the anxiety I have that I couldn't myself. My ex-spouse used to give me a ton of shit because the first 3 days of a vacation I'm still trying to "get used" to the hotel.
In the gym, I'm terrified of using a new piece of equipment, because I know I won't know how it works. I don't attend any sort of organized social dinners or parties, because I see them as a mountain of rules I don't know that I'll be viewed as an asshole for violating.
That's sort of how I feel about every public situation; like everyone has some rule or procedure book I didn't get a copy of.