It's an existential thing
Well put. I never thought of it in those terms, but it seems to work for you, sort of like the concept of "honor" which guided conduct in the 17-19th centuries (but without the need for duels!).
My method, and I make no claims to great virtue, just that I like to think I'm trying my best, is to act as if I were always being watched, even when I know the universe is totally indifferent to my actions.