Genius Bonus: The back story of the matador Finito, the man who fought bulls while having a lifelong terror of them. The real enemy in properly staged corridas is not the bull itself, which can be killed relatively easily by a skilled man. The bullfighter has to perform instead all the complex dance-like actions inches away from the horns, without giving up to his own fear even for a second. The real enemy which he has to conquer each time, for years to come, is fear itself. Hemingway had fought bulls himself in the 1920s and had seen plenty of bullfights. He knew what less informed people, who treat the fight just as a contest between man and beast, used to ignore.
Harsher in Hindsight: All the talk about Robert Jordan's father committing suicide and how he thinks he was a coward for it becomes harsher when you remember Hemingway committed suicide himself.
Nightmare Fuel: Chapter 10. The massacre of the town as told by Pillar. Dear god.
Ugly Cute: Pilar complains how ugly she is, and most of the band agree, while she has had a rich love life with matadors in the past and Robert subconsciously finds her strangely attractive.
Values Dissonance: Not surprising considering when was this book published. Some modern readers don't appreciate Maria treatment as a rape victim, especially with how troublesome the subject has become in recent years.