I had a similar, really great prof, who would always ask for what the next variable would be, so we'd end up with trees and smiley faces. His point was to not make assumptions (c is always a constant etc), but it made the classes more engaging too.
And, somehow every example ended along the lines of "then you hand this to your boss, kick up your feet and have a nice glass of scotch."
He was one of those classic types; you could always catch him for a quick chat 4 minutes before class, as he lit up a cig by the front door. Back when they allowed smoking on campus, anyway.