This has all the makings of an urban myth but here goes. There was a guy who met Andy Warhol at some sort of party/event and asked for an autograph. He then asked Andy to draw a picture - which he did. So the guy had a one-off Andy Warhol original. A few months later the guy went away on holiday and hid his Andy Warhol somewhere safe. When he got back he couldn't remember where it was. Somewhere in his house is an Andy Warhol original that is worth more than his house. As I say it screams "urban myth" but like a lot of urban myths has a streak of believability about it :)