Keith
Moon was an incurable drug addict who may or
may not have been mentally insane. He was a massive prankster, and he had an incredibly unhealthy obsession with explosives, destruction, and destruction involving explosives. Everywhere he went, he got himself and his fellow bandmates in big
trouble with his antics, to the point that they racked up a massive debt and
almost went bankrupt.
During one concert, he had to be replaced because he kept passing out, thanks to his drug abuse. On several other occasions, his insatiable desire for destruction got himself injured quite badly, and he had to be repeatedly "rescued" by his bandmates or whoever happened to find him, who were none too happy to
help him, knowing that he always invoked it upon himself. He ultimately died in 1978 at the age of 32, as a result of his incredibly self-destructive lifestyle. But when he died, his bandmates thought it was a prank; he was THAT much of a prankster. They didn't
even realize it was
legit until they went to his funeral and saw his mother weeping
next to his coffin.