One day, when I was about eight years old, my father and I made a rare trip into Chicago to see a basketball game. My father was a chemist at Argonne National Labs and he worked nights, so we didn't get many chances to spend time together. During a break in the action we went to the bathroom. While we were standing at the urinals, a man came into the bathroom, washed his hands and came over to the urinal next to my father. After a few moments my father said, "So, you're a chemist. Where do you work?" The man looked a little startled at my father's prescience, but soon they were chatting away about organic solvents. As we left the bathroom I asked my father how he'd known that man was a chemist. "Simple," my father said. "A chemist always washes his hands before he goes to the bathroom." -- Scott Turner
(From the "Rest" of RHF)