 Otherwise he sat wherever there was a free space, preferably with a lot of room between himself and other passengers.  He would patiently wait, at every stop checking to see if the middle seat was about to be vacated, and move into it when it was. 
An open seat to Jack was one of the cushioned double chairs, facing towards the front of the bus, on either side of the center aisle.  Jack only considered them “open” if no one was sitting in either of the two chairs because he hated sharing a seat on the bus.  There were many reasons for this selective misanthropy: bad smells, unwanted psychotic conversations, a sense of safety.  There were other factors in his seating choices, but after a year of riding on the bus he no longer bothered justifying the thought process to himself.  So, if he could, Jack would sit opposite the middle doors, throw his right leg up onto the second seat and press his back against the side of the bus, and close his eyes.
Today the seat opposite the middle doors was open.  Seeing this, Jack relaxed slightly and felt happier.  He always thought that any day the middle seat was open was a good day.  With a whisper of a benign smile he moved down the aisle, matching his steps to the rolling of the bus.  
Past an ocean of sensations, the rolling-rumbling-swerving movement of the bus’ floor, Jack saw the faces of the other passengers.  His smile darkened a bit.  He took no displeasure in their presence, did not dislike them, or find them objectionable.  Yet, meeting the eyes of several strangers, his mood was depressed and deadened. 
Riding on the bus was something Jack would never become comfortable with.  Since it was cheap and effortless, the bus attracted a great many destitute, unhappy, unfortunate individuals.  Some were psychotic and homeless wrecks, sleeping wherever they could at night, and carrying all they owned in two or three bags.  Some were hard-luck drunks, going from here to there as cheaply as possible.  Some wore the shirts and hats of minimum wage, customer service employment.  Often they looked ill or malnourished, with sunken eyes and sallow skin.  They looked like ghosts, like after images in a photo, like ripples in a sea of tranquility.   
There were more than a few such individuals on the bus today.  As he moved down the aisle, Jack consciously relaxed his upper body, and scratched his neck against the interior of his thick, red, woolen jacket.  He strolled past seats filled with students, past seats occupied with twenty-some-things both prosperous and poor on their way to work, past elderly men and women, and past the ghostly individuals with their empty, disturbed eyes.
 As he made his way to his favourite seat he was cheered by the sight of the students.  Jack found it hard not to be entertained at the sight of them. 