It's the way that Steph's teacher called her out, saying that she hoped she studied in front of the whole class. It's the way that Steph's father said that he wanted to have an intelligent conversation with her, so she should shut up. It's the way that Steph herself says, "I'm actually the smart one in my friend group, if you can believe it."

It's the way that Pete says, "She's smarter than she thinks she is" and "You're as smart as I know you are" (could be paraphrased, idk my digital ticket is gone) and got excited over a C+ with her.

Something something everyone telling Steph she's not smart so much that she believes it herself something something Pete seeing that she actually is smart