Sorry is a reflex
British people say 'sorry' when you bump into them. And when they bump into you. And when they need to pass. And when they disagree. 'Sorry' is punctuation, not apology.
Etiquette in United Kingdom is mostly invisible until you break it. Greetings, gestures, dining manners and the social cues locals expect are worth learning before you arrive.
In United Kingdom, etiquette comes down to a few things: sorry is a reflex, understatement is communication, and rounds at the pub.
British people say 'sorry' when you bump into them. And when they bump into you. And when they need to pass. And when they disagree. 'Sorry' is punctuation, not apology.
'Not bad' means excellent. 'Quite good' means acceptable. 'Interesting' might mean terrible. British communication is indirect and layered. Listen to tone, not words.
If someone buys you a drink, you're in a round. You buy the next one. Leaving before your round is social death. 'Can I get you one?' is how it starts.