It sure hurts a hell of a lot. However blood, flesh, and bone? They all heal whether you like it or not. Do something miniscule that you despise. Treat yourself at a gas station. These little wins and losses stack up in a way, that if mismanaged, can crush you. Smoke if you want to. Fight your addictions. Don't be made a fool by your tools; you'll morph into a tweaking ghoul if you fail.