Reading Probert's biography gives one a glimpse into why these guys struggle with addiction, they leave home to play junior, while away they start drinking frequently with the other players who are all in the same situation. Their entire lives are based on hockey, so they do whatever it takes to be ready to play, there is not backup plan because they have spent the formative years of their lives away from school and other social structures. There are some that can handle this, but many of the NHL guys develop serious addiction issues because they do not know any other way of life other than to be one of the boys in the locker room.