It's ironic that a relatively new holiday which celebrates a drug known for its short term memory loss has such an incredibly hazy history, but that is exactly the case with 4/20.
4/20 is a relatively recent phenomenon, yet its origins are more obscure than most ancient holidays. Everybody knows that Christmas is celebrated on December 25th, because that's when Jesus died, and Easter is always on April 16th because that's what some Jewish dude told me once. But why is 420 called "420," and not "430" or "520" or "660?"
I know what you're thinking, "Because nobody gets high on June 60th, you morron." But you're missing the point. (And if I'm the moron, why did you spell it with two R's you fucking idiot?) I wanted to know the origins of this magical number. Why is this digit even associated with marijuana culture? After extensive research/napping, I was able to find the five main theories behind this magical number. And here they are, in no particular order, other than reverse alphabetical:>