Charlie was loosely based on Chbosky himself. In the novel, Chbosky included much of his own memories from the time he lived in Pittsburgh. The other characters were manifestations of people Chbosky had known throughout his life; Chbosky focused on people's struggles and what they are passionate about, attempting to pin down the very nature of each of the characters. The characters of Sam and Patrick were an "amalgamate and celebration" of several people Chbosky has met; Sam was based on girls who confided in him, and Patrick was "all the kids I knew who were gay and finding their way to their own identity."