While surfing on the net (wondering myself how I do this as a full time family guy), I stumbled upon a nice avatar line:
"I ignore some people in Real Life, because I am too old to dig holes in the woods"
And the second one is one of my favourites (got it as a metal sign nailed to my eating rooms wall):
"Keep on smiling, you can´t kill them all".
So in case you face one of those all-present smartasses at work, get cut in traffic while driving your car or simply stand in line at the supermarket and somebody "accidentally" bumps into you to let you knopw, that you still have 1 more inch of space to the person in front of you, just remember those lines. Makes life easier