Everyone understands rules and procedures and laws.
Common courtesy is more of a mystery. "Common" means something you do for family members, good friends, co-workers? Does it include the shoppers at the mall, the grocery store? What about the panhandler on the medium at the red light when even though it is 102 degree in August and the air conditioner in your car is broken, you roll up the windows and stare straight ahead. Or racing to the office with a box of donuts, the fellow who sleeps beneath the awning of the machine parts store on Calvert Street raises his hand? Is it common courtesy to offer him a donut?
We all know where "common" courtesy begins; where does it stop?
How do you decide that one person deserves compassion, consideration, and another does not? How is one person determined to be inhuman? What makes us shift from polite and waving in the Dodge caravan carrying several children trying to merge versus inching bumper to bumper to make sure the Ford 150 pickup truck with gun rack and rebel flag does not merge. Or perhaps it's the tractor trailer or the Jaguar or the 1957 Chevy with historic tags? Why can't we be generous to all? What rears up and pushes our molars together, grits the teeth, pinches the lips, hunches the shoulders?
Why can't common courtesy be "common" for all.