Interesting I stopped cannabis because I felt that when I smoked it I just became a lazy blob. It's one drug that when I stopped, I never looked back and still have no desire to partake.
I've never used a needle for anything. That was one of the few boundaries I had. I've seen people shoot up and it was not appealing.
One guy shot up and basically passed out and fell to the floor. No one seemed to care, though I was scared he was dead. some time later he stood up and was ready for more. That just reinforced my decision to never shoot up.