I wasn't going to say anything else, but I can't help myself. Someone said that if you drink how could you have enough willpower to be vegan? Well when you drink or do any other "vice" for that matter you are making a personal decision about how to treat YOUR body. Where as being vegan is about not mistreating another beings body. I think that is the main difference. Also, in moderation, most "vices" can be a very fun experience. It's those with no self control that ruin it for everyone else.