- Dropping an Airborne tablet into a cup of coffee refilled with water without first rinsing out the coffee

- Walking full speed into a horizontal pole mounted two inches above eye level

- Okay, walking full speed into a horizontal pole mounted at any level

- Collecting tiny, shiny pebbles from a beach in Oregon and then dumping them in your purse where six months later one of them can become lodged in the little slot on your cell phone where the charger plug goes, forcing you to spend twenty minutes picking at it with a pushpin until the pebble finally comes loose, but then you drop the pushpin on the floor and because it's clear and roll-y it takes you another five minutes to find it and by then you just really need a nap.