My sister was drinking coffee and typing on her laptop one day when she knocked her coffee over and it spilled all over her keyboard. The coffee started dripping between the keys and in a desperate leap to save both the laptop and the paper she was working on she started blotting the keyboard with a nearby napkin.
After a little while the computer pops up a dialog. "Do you want to turn on sticky keys?"
Five minutes later I get a phone call from my sister...
"How the heck did the computer know my keys were sticky?"
(For anyone not familiar with stickykeys it's an accessibility feature for Windows that can be turned on by pressing the shift key on your keyboard five times)