The answer is that he usually does not intend to become an addict. You don’t wake up one morning and decide to be a drug addict. It takes at least three months’ shooting twice a day to get any habit at all. And you don’t really know what junk sickness is until you have had several habits. It took me almost six months to get my first habit, and then the withdrawal symptoms were mild. I think it no exaggeration to say it takes about a year and several hundred injections to make an addict.
The questions, of course, could be asked: Why did you ever try narcotics? Why did you continue using it long enough to become an addict? You become a narcotics addict because you do not have strong motivations in the other direction. Junk wins by default. I tried it as a matter of curiosity. I drifted along taking shots when I could score. I ended up hooked. Most addicts I have talked to report a similar experience. They did not start using drugs for any reason they can remember. They just drifted along until they got hooked. If you have never been addicted, you can have no clear idea what it means to need junk with the addict’s special need. You don’t decide to be an addict. One morning you wake up sick and you’re an addict. (Junky, Prologue, p. xxxviii)”