Here's the horrible thing about drug addiction and alcoholism: No one takes that first drink, toke, pill or hit thinking, "Yeah, I'm gonna become an addict! Alright!". Everyone thinks they're mature enough to handle it. However, some have a metabolic pre-disposition (family history is a good predictor) where the first time the alcohol or drug hits their bloodstream, their brain says, "Yes! This is what I've been missing all this time!". No one knows if they are one of these people until they start. For those that have addictive tendencies, from that point on, it's not about moral responsibility not to drink or drug, it's a daily struggle to fight those thoughts in the brain telling them, "I need that drink/drug!". I had a grandfather who was an alcoholic but fortunately I didn't inherit his problem. I can have a drink without the need to have a second or third and never had any desire to use drugs although a lot of my friends smoked weed in high school and college.