I once installed sl on a server. Completely forgot I put it there. It laid there dormant for MONTHS without anyone tripping over it. Then....it happened.

"What the...why is my screen blac--is that a train-AW DAMMIT".

That person was me. The guy who installed the damn thing.

The progression from confusion, to curiosity, to realization that I had in fact...just played myself was kind of amusing in the moment.