I dunno what it is but once I see the person who comes out of the bathroom stall after taking a dump, I can never look at them the same.
I know.
I know.
We all take shits.
And seriously me, I wait until I know noone else is in the bathroom before I leave the stall.
I know that's lame too but hey, the curtain must fall somewhere.
Point being, people are gross to begin with.
Then add the fact that they take nasty and stinky dumps.