* AdaptationDisplacement: Few people know that ''Flowers'' was originally a short story.
* FreudWasRight: Poor Charlie. Upon seeing his sister in the bathtub as a child, was struck by her (seeming) lack of genitalia. Not only did he come to the conclusion that their parents [[{{GroinAttack}} removed it to punish her]], but his mother caught him and...[[BrotherSisterIncest jumped to the wrong conclusion.]] This earned him a traumatic experience with a knife and a deep-seated fear that he'd be castrated one day as well. Anytime he tries to have sex, bam! Traumatic memories.
* HoYay: The cuddling Warren inhabitant boys.
* ItWasHisSled / AllThereIsToKnowAboutTheCryingGame: One of the few things people who haven't read the book know about it is that Charlie is a retarded man who becomes intelligent [[spoiler:and reverted back to how he was beforehand.]]
* ShootTheShaggyDog
* SomeAnvilsNeedToBeDropped: The book is very clear that the treatment of the mentally disabled by abled people is horrific.
* TheWoobie: Charlie, obviously. [[spoiler:Realizes that his so-called friends were simply using him as a toy, finally reaches genius levels of intelligence, only to lose it, and starts to forget almost all the notable events that happened to him towards the end.]]