In one of the earliest seasons of the Simpsons, Lisa has a substitute teacher (voiced by Dustin Hoffman) who she falls in love with on every emotional and intellectual level she has. He's magic. He understands her, stimulates her, and deals patiently with her grade-school crush.
Like any sub, he can't stay around. Lisa's teacher gets over her illness and shows up in class. Lisa runs to find him, and they have a scene at the train station, where he sadly, patiently, explains that he is needed for the slowest kids, the troubled kids, the trouble kids.
"But what about ME?" Lisa demands. Why is it always someone else's turn? When it is her turn? What will happen to her? The teacher gives her a note, and says that everything's going to be okay. Wait till the train goes, and read the note. And away he goes, smaller and smaller, out of sight, and before that happens, she has unfolded the paper and read the words:
"You are Lisa Simpson."