When I go in or out of the bathroom in our office building and am meeting a guy coming in/out (opposite direction as me) at the same time, they always jump, like I've scared them. I never am surprised and I'm thinking it is all of the years of stepping on pheasant or into a covey of quail that keeps me from being surprised. I knew there had to be some benefit to that down the road, just never knew what it was.

Jumping back is a defensive mechanism from predators, it enables the prey to react subconsciously and potentially escape a deadly scenario.

You have apparently lost that mechanism and suffer from delayed reaction time, leaving you more at risk of a frontal attack

You won't startle the idiots that enter whistling as loud as possible. Calm the hell down Dude.

I failed to mention I always have my EDC drawn just in case they try to make a move as I come through or at the urinal.

'At a boy.