Ineed a 1000 word fiction story for my creative writing class using ''show don't tell"

The boy was asked to tell about his best points and the good points of his characters.  However, when the boy overexaggerated his best points regarding his academics, hobbies, dancing skills, and the skills for handling the situation when someone needs help. The teacher on this asked him about the evidences and the proofs or the related incidents from the past. The teacher on this said that the student must show and not tell.