I'll let you in on a secret... About the only negative "side effects" of hrb is 1) You get lazy. Sometimes not as much as others, but herb tends to make you lazy (there are exceptions, I'm talking in general though) 2) Weed will such up your money quick as fuck. No two ways about it 3) IF you get caught your record will go south real quick.

Anyways there is no reason that weed would necessarily prevent you from reaching a 'sucessful' position in life, indeed it is feasible it would help. But it can hurt your efforts. If your wary of the side effects, and responsible with your money you have nothing to worry about... Just don't get carried away