About two hours ago, I was struck by the common urge to make myself a cup of tea. So, I poured some water into my teakettle and set it on the stove to boil, then left it in favor of stimulating activity. Forty five minutes later, I noticed that the kettle hadn't made any noise to indicate rediness yet, so I went downstairs to check whether everything was alright.
The water had boiled almost all away, and I'd left the top off the kettle. The steam had been escaping through the hole in the top, rather than the whistle.
All that work, all that gasmoney, for nothing. *weeps*