Riddle me this!

Ladies bear with me. The following topic really has me stumped, despite its somewhat awkward nature. Imagine a men's restroom. Imagine some chap walking into this restroom to pee, before him a row of unoccupied urinals beckoning to him to fulfill the measure of their creation. Yet to your astonishment this chap promptly bypasses the urinals and proceeds to the nearest open stall where you hear him lift the seat and proceed to void. Puzzled you stand in stupefied silence thinking, "did I miss something"? then "why does a grown man bypass the urinals for a stall"?
I don't think I need to mention what a horrific scourge a stall can be, at times it makes anthrax exposure seem like an appealing alternative. Now imagine seeing this scene repeated in various restrooms over a long period of time. "Did I miss a memo"? you wonder. Mystified you begin working on theories, but nothing adds up. "Do they like reading the graffiti on the stall walls................it can't be", " maybe stage fright............but its not shoulder to shoulder traffic, they have at least a one urinal cushion on each side, often the whole row"!, "perhaps a phobia of urinal cakes..........now your just being ridiculous"! As you stand in the middle of the restroom staring blankly into space considering conspiracy theories you fail to notice the aforementioned chap leave the stall and give you a quizative look before he leaves, (or if your really lucky washes his hands). What's more your will never know of his mental query as he passes by you, " what's with all the spaced out dudes standing in men's rooms....I just hope he doesn't notice how big my butt is". As the door shuts you snap out of you stupor and realize the subject has left the room, you then wonder "did he flush"? "I don't remember hearing a flush........then again I don't recall anything since that dude walked into the room".
Really though, being the sick, twisted, freak I am, I'm puzzled.