If I had to offer up a one sentence definition of addiction, I'd call it a form of mourning for the irrecoverable glories of the first time...addiction can show us what is deeply suspect about nostalgia. That drive to return to the past isn't an innocent one. It's about stopping your passage to the future, it's a symptom of fear of death, and the love of predictable experience. And the love of predictable experience, not the drug itself, is the major damage done to users.