I watched a movie years ago (don’t even remember the name) where a guy and gal were having lunch or something and he says...what do you see? She looks around and says I don’t know then he proceeded to tell her what everyone around them was wearing and doing. Don’t know why but it stuck with me. Ever since when I go somewhere I see how much I can remember...exits, people, etc. before I sit down. Kind of a game I play in my mind. Never thought it would be useful. What a shame.
I think you are referring to “The Bourne Identity” - it has a scene like that. What convinced me was the fire during the concert of the band “Great White” caused by pyrotechnics in a small crowded bar. Most people died because everyone was trying to escape through the front door and it got all clogged up. Several people were able to escape through the back exits unobstructed. Ever since then I always scope out back and side exit doors and even get up to look for them if they are not obvious. If something like that happens I want to be escaping in the opposite direction everyone else is running.