Bad: Wasting water by walking away and leaving the faucet running.
Worse: Realizing too late that the water has now overflowed the sink and is running onto the floor.
Worse still: Opening the cabinet to get out some towels to start drying up the water... and realizing that the towels are already wet from the water running down onto them.
Even worse than that: Pulling out the bottom drawer under the towels to discover that you've miraculously transformed the box of Q-tips into a small, rectangular bathtub.
Absolutely the worst: Realizing that despite the fact that you have a six-year-old and a two-year-old, who by all rights really ought to be the cause of any such catastrophes that occur in your house, this event cannot in any way be considered their fault, and the Floppy Hat of Abject Stupidity must be worn by you and you alone.