Quote 1
The family section [of the newspaper] ran a regular feature about kids on their birthdays, and my mother had called in some info. The last sentence read: "As a hobby, Leo Borlock collects porcupine neckties" (Prologue.4).
Porcupine ties are an unusual thing to collect. No wonder the poor kid only has one tie in his collection. But still, this is a quirk that Leo maintains all his life, even when he enters high school and the pressures to conform are the greatest.
Quote 2
When someone turned and nodded, I felt grateful. If someone spoke to me, especially if I had not spoken first, I wanted to cry. I had never realized how much I needed the attention of others to confirm my own presence (23.3).
Leo really starts to feel isolated by the fact that so few people are talking to him lately. He is very insightful when he realizes that the reason this affects him so much is because his identity is based on his involvement in the groups around him. If no one notices you, are you anyone at all?
Quote 3
Her back was to us, so I couldn't see her face. No one sat with her, but at the tables next to hers kids were cramming two to a seat. She didn't seem to notice. She seemed marooned in a sea of staring, buzzing faces (1.25).
Here's Leo's rather vivid description of how Mica High's society responds to Stargirl's first day in the cafeteria. She is the new girl and very different, so everyone's a bit on edge. She has ruffled their feathers.