I have a British colleague who has lived outside the UK for almost a decade and she still apologizes when other people bump into her. Watched a stranger run into her shoulder at a coffee shop and she said "sorry" before he did. It was reflexive. She didn't even register it. That's the one I've noticed most often. There seem to be a few of these that are wired into Brits so deeply that no amount of time abroad takes them out.

Brits who've lived in another country for a while, what's yours? The phrase, the social reflex, the small thing you keep doing in places where it doesn't really make sense, the moment that immediately tells people you grew up there.