Thompson's eye for the ludicrous and incongruous obviously was already developed at this early stage in his career, and so too was his acidulous pen: "What passed for society was a loud, giddy whirl of thieves and pretentious hustlers, a dull sideshow full of quacks and philistines with gimp mentalities." The images that Thompson later would refine in Las Vegas and on the campaign trail had already taken shape in his mind. Yet his eyes were clear enough to see the beauties of a tiny island called Vieques and to know that, doing hack work for a developer, he "was being paid $25 a day to ruin the only place I'd seen in ten years where I felt a sense of peace."
In later years, as Thompson refined and embellished his prose, as he invented and quickly personified the gonzo style, it became harder and harder to remember that at the core of this hard-drinking, hard-talking, hard-living man is a moralist, a Puritan, even an innocent. The best thing about "The Rum Diary" is that it gives us this side of him without apology, even, I suspect, with a kind of pride. For this reason it is a lovely book and a useful contribution to a body of work that's likely to gain substance and weight with the passing of time.
Depp may be the best actor to bring out this hidden side of Thompson. Not only did the two become close friends after Depp potrayed Thompson in the 1998 film “Fear and Loathing in Las Vegas,” Depp also had a hand in the publication of the novel. In an interview with the Arizona Republic, Depp said he discovered the manuscript when visiting the author’s Colorado home.
I was preparing for "Fear and Loathing," and we were in the war room (at Thompson's house) looking through boxes for the manuscript of "Fear and Loathing," which included, like, cocktail napkins and cherry stems and bandages, and all the weirdest stuff in the world. Suddenly I happened upon this other box that I broke open and, right on top there, stuffed amongst these papers, was "The Rum Diary." And we started reading it, the two of us, cross-legged on the floor. And I said, "Hunter, you're insane, man, this is (expletive) great writing. You need to publish this. I don't care when you wrote it. Let's publish it."
In making the movie, Depp is making good on one of the author’s last wishes — Thompson committed suicide in 2005, at the age of 67.