How did 420 get to be slang for cannabis?
Well, it started 50 years ago in 1971at San Rafael High School in California's Marin County with 5 students who hung out near a wall on campus, calling themselves the "Waldos". One of the Waldos was given a treasure map to a field of weed and everyday, they would meet after school at 4:20 near a statue of Louis Pasteur to get high and set out on their quest to find the field. During the day, as they passed each other going to class, they would say "420Louie" to remind each other about their get together. The Waldos eventually dropped "Louie" and kept 420 as their secret slang for weed. It didn't stay a secret for long, though. Soon, it was picked up by others spreading from city to city, state to state and country to country for over 50 years.
To learn more, go to https://420waldos.com
By the way, they never found that field of weed.