It's a tale as old as time. After a long day of staring at your screen in anger, you're standing (or maybe sitting, crying) in the shower. Just trying to wash away the agony of the day. As you lather up your hair with sweet-smelling shampoo, there it is. A “Eureka!” moment. No, not the meaning of life. But the perfect zinger that would have absolutely destroyed that annoying bully in the office cafeteria, or perhaps that obnoxious Twitter troll you wanted to clobber with words. It's unfortunate…