In the beginning, before you pick up a habit and become addicted, yeah taking opiates makes you wanna do things, and does give you this motivation/confidence.
However, as you start using more and more, stronger opiates and higher doses, that goes away big time. Once you get physically and mentally addicted, it does the exact opposite, it saps away all your motivation and drive, all your passion. You'll find yourself constantly saying you'll use and then do this, or do that, blah blah, but then you just do absolutely nothing.