Finally, I've conquered all 754 pages (not including appendix and index) of Che Guevara, a Revolutionary Life.
Reinaldo Arenas was a Cuban poet and author who, as a gay man and as a writer who smuggled his work out of the country to be published, suffered greatly in Fidel Castro's Cuba. Eventually, he fled Cuba for the United States during the Mariel boat lift and, dying of AIDS-related causes, killed himself in New York in 1980.
When he was 15, Arenas was also a fighter in Castro's rebel Army.
About halfway through Che, Arenas makes his only appearance. Jon Lee Anderson has a paragraph mentioning Arenas and quoting a description from his memoir, Before Night Falls. But Arenas' case speaks to the fact that no one, except maybe Che, knew what the revolution was leading to. There were certainly other guerilla fighters who fled Cuba after Castro took power. People were so unhappy under Fulgencio Batista, though, that they were willing to fight against him, even if it wasn't clear what they were fighting for.