Mine is a really, really dark memory, actually it was really recent.
I went to the dells for a week, and we stopped to see lake delton. Due to a recent dam breaking all of the water drained out. When I saw it, it was empty. There were trees, stumps, and destroyed houses all laying in the sand and mud that used to be the lake.
Then it came to me, this is what I wanted the world to look like. 0_o