By the way, I should mention that it's not all wine and roses. There is such a thing as too much weed. If it's giving you panic attacks, it's too much. If you're getting bad headaches, it's too much. If you can't follow conversations, it's too much.
I had a strict policy of only working when absolutely cold sober. I had full control over all of my organization's servers, and I could inadvertently cause enough damage to destroy the company with a single mistyped command. If I were high at the time, I would have deserved what would have happened to me.
Plus yeah, not good for mania. I find it's only useful for the depression.
Also, inhaling combustion products is never going to be good for you.