The US wasn’t even the first to ban it. In 1937 Marijuana Tax act was passed that effectively prohobited it, but a full ban came in 1970. Countries that banned it before 1937 include, but are not limited to: Thailand, Irish free state, Romania, UK, Indonesia, Australia, Lebanon, Sudan, Italy, Panama, Canada, South Africa, Mexico, Jamaica, Greece, Singapore…
This. In general it refers to social awkwardness related to autism. Heard it used mostly as a slur/insult where I live.