I think it's mostly his style, in many senses of the word, which keep this thing so readable. Otherwise, he'd have naturally had long dry spells barely worth recording. It may have helped that he's said to have written it all out in 2 days or so.
I've heard it suggested that he couldn't have lived as much life as recorded here, but it feels to me as if he left a great deal out. Once he was on South American shores again, he apparently went full-party, with really professional riff-raff, and any writing he could have done was sadly lost in the clubs.