Why is Cannabis called Marijuana?

So why does everyone refer to cannabis as marijuana?

Turns out, the name marijuana comes from the Mexican slang term for cannabis, which is believed to have originally been derived from the Spanish pronunciation of the names Mary and Jane.

Why Mary and Jane you ask? Why not any of the other popular name combinations like Mary Anne or Mary Sue? Well really, no one knows, except for the fact that the two names were also common Mexican military slang for a prostitute or brothel. Go figure.