Well, it *was* a wake-up call, I suppose.

After hitting the snooze alarm a couple of times, I eventually dragged my bleary butt out of bed and to the shower.
I noticed that one of the wife's shampoo bottles had fallen onto the tub floor near the drain. I leaned in to pick it up, and started the water (our hot water takes a while in the bathroom).

That's when I found out that the wife had left the shower lever in the "on" position. As the frigid water hit my unprepared head.

Ouch

An obscure joke.
(If it helps, that's Alice Liddell.)