Normalcy bias — it's an absolute killer. The same cognitive failure that has people in a fire thinking it's "just part of the show", or "just something in the kitchen", until it is too late, and panic overtakes everyone. I've never seen a story of a fire where someone in the situation said "I wasn't sure what was going on, but it didn't seem good so I left early, I'm alive because I did!".

Normalcy bias can kill us all if we aren't careful.