Starting tomorrow, people in New Jersey will be able to legally purchase marijuana for recreational use. The state's decision is part of a larger trend across the United States; according to the National Conference of State Legislatures, pot is legal for medicinal use in 37 states, and non-medicinal weed is legal (for adults) in 18 of those states. 

And if you know anything about weed culture, you're probably amused -- and maybe disappointed -- by the timing of New Jersey's green light. But you shouldn't be. Tomorrow is April 21st, or 4/21. Today is 4/20, and the number 420 has long been associated with smoking up. New Jersey seemingly had a great opportunity -- they could have rung in the new era by celebrating with those who mark this informal marijuana holiday. But the cultural draw of 420 proved too deep for the state to handle: a state regulator told the local press that "selecting 4/20 for opening day would have presented unmanageable logistical challenges for patients and other buyers, surrounding communities, and for municipalities," so they went with 4/21 instead.

That's how powerful 420 is in the marijuana world. But where did it come from?

According to those who would know, it all started with a treasure map. Maybe.

While pot is increasingly legal today, it most definitely was not in the late 1960s and into the 1970s. Officials often turned a blind eye to recreational use -- for example, a contemporaneous Associated Press report about 1969's Woodstock festival stated that "weed was in better supply than water," and it's generally believed that no one there was arrested for smoking pot. But while marijuana was easy to obtain at rural New York music festivals, the same wasn't the case at many suburban schools throughout the United States. Just ask Steve Capper.

In 1971, Capper and four of his friends were high school students living in San Rafael, California, not too far outside of San Francisco. And like many other kids their age, they liked to smoke up, and probably a bit too much. As Capper told SFGate in 2017, "back then we spent every day of our lives worrying about getting busted. Going to buy was a really secret thing." Once they had their day's supply, though, it was smooth sailing -- the quintet would hang out behind a wall just off the school grounds and get high. The ritual became such a large part of their identities at the time that they nicknamed themselves the "Waldos," in reference to their behind-the-wall gathering spot.

But, again, getting the pot was a challenge. The Waldos didn't want to risk arrest -- who would? -- and as luck would have it, they claim, there was another way for them to obtain some weed... maybe. The Waldos' story -- and to be clear, this could be an elaborate (but fun) lie -- someone was growing a large stash somewhere on Point Reyes, a peninsula jutting out into the Pacific not too far from San Rafael. According to the Huffington Post, "a Coast Guard service member could no longer tend his plot of marijuana plants near the Point Reyes Peninsula Coast Guard station" and didn't want to see it go to waste; per other accounts, the origins of the mythical plot are unknown. But through some connections (and probably, older brothers), the Waldos learned about this bounty of free marijuana and were given a crudely drawn map to help them find it.

Whether the map or the crop actually exist is something only the Waldos know, but real or fake, they ran with it. As their story goes, on most days at 4:20 in the afternoon, they met up at a statue of Louis Pasteur after school to adventure out to Point Reyes. The tradition became an in-joke among the five and, while passing each other in the halls of their school, they'd call out to one another "4:20 Louis!" While the other kids at school probably didn't know about the Goonies-like adventure the Waldos were planning (or imagining), they certainly knew that the Waldos were potheads. The code phrase was truncated over time and the "Louis" part of the quip was lost, but for kids at San Rafael High, "4:20" became known as the time to smoke up.

Why 420 spread outside of San Rafael is anyone's guess -- as is the fate of the Point Reyes pot plot. If it existed, the Waldos never found it (or if they did, they kept it to themselves).