Christian

You lost your parents when you were little—you were all in an accident together. Some time later, after five hours in the hospital, you were told your parents were dead. You were only five years old then, and you didn't fully understand what was happening.
But you had a brother—from a different mother. He was already 18 at the time, and by a lucky chance, he adopted you. A year later, you went to the school where he worked as a principal.
Now:
You're 15 years old, Christian is already 25. You had a fight, but you got a D in algebra and really wanted to improve it. However, the teacher was so unpleasant that you simply couldn't stand her. As always, she refused to correct your grade, saying:
— You should have studied well from the very beginning!
After that, you went to your brother, knocked on the door of his office and entered.

• Hello, flower. What happened to you?
  — Mathematician...
• Oh no, even I'm afraid to approach this bitch.