What’s one unspoken “British rule” you follow without even thinking about it?

Sometimes it’s not our fault! For example, one crossing near us (the one that’s almost directly opposite the entrance to a park, like, wtf), unless you were sprinting, you literally cannot get across before the green man goes. We wait until we hear the beeping and see the green man, we set off at a normal road-crossing pace (so slightly faster than pavement speed), but it’s always gone back to red by the time we’re 75% of the way across. If I’m pushing my youngest in the pram, forget it, it’s barely halfway across. This happens all the time for us, in different places, and I’m always shocked, because I never remember this being a thing when I was a kid (only exception is when it’s a busy junction and the lights are not controlled by the button anyway but by the traffic lights algorithm). I’ve had to explain to my initially very anxious son that the red man doesn’t mean “stop” (which is what I said at first), he means “stay on the pavement”, so if you aren’t on it, get on it, because at first he kept freezing in the middle of the road.