Edit: The person who posted this video on YouTube told me that he wishes for it not to be posted on other sites... Mods can delete this thread as it is now pointless.
While abuse can definitely lead to people perpetuating a cycle of violence in their own lives and others, the old chestnut about how all bullies must have been bullied themselves isn't really true in every case, or even the majority of cases. This is a pretty okay video though, I guess. Though how would the teen at the end buy his own booze?
I don't think that the intention was for the teen to buy his own booze, I think it was more to foreshadow the future.