It also seems like you don’t understand that it being banned 50 years ago is not the same as it being banned for 50 years.
Dude, it is literally illegal at the federal level at this very moment. If you use marijuana, and you buy a firearm, you are a felon. The ban may not be fully enforced in some states right now, but the feds can, at any moment, and on a whim, go into California and Colorado and arrest every single person working at a dispensary and charge them under federal drug trafficking laws, and send every single one of them to prison for life.
I would ask what you’re on, but I’m pretty sure I can guess.