Any black belts here who smoke weed and cigars? (really stupid question, but I gotta know)

I think I've met Kung Fu and Karate black belts who smoke a lot of things, but I'm seriously worried that smoking fucks up my rolling stamina too much. On the other hand, I seem to have good stamina, my strength goes down after an hour of rolling but I can still keep going for about another hour. To be fair, I'm only 20. Maybe it'll catch up to me when I get old, but I'm wondering if I could get a BJJ Black Belt before that happens? If not, could I at least make it to purple belt?