A wallflower is someone who's so shy that they typically stand or sit alone rather than engaging with a larger group. If you tend to be introverted and a bit awkward at parties, you might describe yourself as a wallflower.

Throughout the 1991–1992 school year, Charlie, the fifteen-year-old (later sixteen-year-old) protagonist, begins writing letters about his own life to an unknown recipient addressed, "Dear Friend." In these letters, he discusses his freshman year of high school and his struggles with two traumatic experiences: the suicide of his only middle-school friend, Michael Dobson, and the death of his favorite aunt, Helen who keeps haunting him.

He meet new friends named Patrick, the queer whose having a secretly affair with his fellow senior jock. And Sam, Patrick's stepsister, revealed to be engaged on sexually abusive childhood. During those times, Charlie drastically experienced changes on his environment that is no longer bond on his comfort zone. The adventurous phase of finding yourself. Enjoying what youth has to offer. Wild and free even if its temporarilyf filling those gaps and holes. Charlie seems making layers and layers on his mind just to cover up his terrible past.

The book addresses a range of themes of teenage reality and nostalgia. Which also include drugs, friendship, body image, first love, suicide, eating disorders, mental condition and sexuality. Chbosky highlights the importance of entertainment in adolescence: "Books, songs, and movies are more than [just] entertainment when we're young: They help all of us discover who we are, what we believe, and what we hope our life can be. Which totally relatable during my time here at college. 

It is also about acceptance and forgiveness for yourself. Charlie subconsciously blaming himself of the death of someone he loves yet, he find a desire to continue to live because of that. He look forward when certain people pull him from those orifices. It is always important that we would be surrounded by a lot of people. It is important we have someone by our side. Strength comes from people. And we should cherished them. Cherished what we had, even if its just a fleeting moments.