One truism of addiction science is that long-term abuse rewires your brain and changes its chemistry, which is why triggers (or “associated stimuli,” in scientific parlance) are major risk factors for relapse. But these changes can be reversed over time. Walking past the apartment where my dealer used to live didn’t make me want to score; it made me feel as if I was in a phantasmagoria of two crosshatched worlds—but I was the only person who could see both realities. None of my colleagues at MIT, no one in the science writing community I lean on for professional advice and support, none of the people who’ve worked on my books has ever seen me slip into that other world.
(whole article, but the crosshatched-worlds thing is what really struck me)