what she means:
its september again and i still havent gotten a hogwarts letter and i know i shouldnt have my self esteem reliant upon a fictional school's fictional acceptance letter that i know rationally will never come but its such a worry anyway and i cant control this insatiable wish to go and
You’re going to go through life thinking that girls don’t like you because you’re a Slytherin. And I want you to know, from the bottom of my heart, that that won’t be true. It’ll be because you’re an asshole.
Lily Evans, age 16, probably. [to Severus Snape]