Having evacuated a plane, no matter how orderly, I can assure you it is rather terrifying. Jumping into that slide is a long way down, which is why so many people tend to end up with broken bones from the evacuation. When you look down into the slide your natural tendency is to want to crouch down and scoot into it but you have to jump into it, at which point you just say, what the hell, I have no choice and do it.