3 ideas
Don understands his own drinking with clinical precision. That intelligence never works as a brake; it is drafted into the addiction's service, producing rationalizations, clever schemes for getting money, and elaborate hiding places for bottles. Insight becomes a tool of the compulsion rather than a way out of it.
Early in each drunk, Don's mind produces vivid, grandiose visions of the brilliant novel he will write, including one about his own drinking. Having vividly imagined the book, he feels the reward of having written it, and so the imagining displaces the writing. The drink sells itself as the key to creativity while it actually uses up the ambition it seems to feed.
The novel refuses the standard shape of an addiction story, in which hitting bottom brings insight and then recovery. Don's worst humiliations bring only exhaustion, and the binge ends because a bottle is back within reach, not because anything has changed. Read this way, the addict's 'bottom' is one more point in a cycle, and the arc of redemption is a story observers tell, not something the drinker experiences from inside.