Can you become an FBI agent if you've smoked?

Okay, I'm 16 and am 90% sure I'm going to pursue a path as a FBI agent. My uncle is pretty high in the FBI and was talking to me about the degrees and all kind of credentials that I will need. He mentioned that you can't have smoked (weed) in the past 15 years. I've tried weed one time, like literally once not one time with multiple "hits" I mean one time one hit. And I will never do it again. Will this affect my chances?