Early on in the narrative, Leo is able to identify why Stargirl has captured the imagination of the students at Mica Area High School. Part of the reason has to do with the school's social setting itself:
We all wore the same clothes, talked the same way, ate the same food, listened to the same music. Even our dorks and nerds had an MAHS stamp on them. If we happened to somehow distinguish ourselves, we quickly snapped back into place, like rubber bands.
It becomes evident that Stargirl breaks this mold. Her dancing around the cafeteria, as well as her insistence on "being herself" pose a fundamental challenge to the MAHS social scene. She is so authentic in being herself that she has managed to capture the imagination of the students at the high school. It is here in which Leo notes that students begin to find interest in her. As evident in Stargir's exuberance at the football game, Leo makes clear that the students at MAHS actually liked having Stargirl "in their lives." Stargirl made "each day an adventure." Her spirit of uniqueness is where students found their imaginations captured. It is here in which Leo feels that Stargirl has become so popular with students who are used to being "snapped back into place, like rubber bands." Stargirl appears to be an anomaly to this condition.