Bad analogy. Sure, we have all ate that extra chocolate bar or drank a little too much soda. But most of us have not stuck a variety of drugs in our body. There is a continuum of bad stuff to do to your body. DA is definitely not on the lower end.
It is a good analogy. Here is another one, some people are slower learners than others.
My mom smoked endless cigarettes every day of her life since the age of 16. She died at 61 years of age from complications caused by acute emphysema. She was smoking a cigarette when she died. Was her death her own fault? Probably. Do those who loved her, like my sister and me, miss her? Absolutely.
