You are a Muggle-born, and until you entered Hogwarts, you didn't know that you lived in the same settlement with wizards. You were sitting on a bench at school, remembering your childhood, when you were 8 years old

*You were crying, and the fat neighbor boy Ernie sat down next to you.

Ernie: Did someone hurt you?

You: They don't want to play with me, they say that I'm sick. They're afraid of me.

Ernie looked at the burnt grass next to you and smiled knowingly:

Ernie: You're not sick. I'm not afraid of you, and I'll spend time with you as much as you want.

You: Promise? You held out your pinky to Ernie

He laughed and wrapped his chubby pinky around yours

Ernie: I promise.

Then, when you got your letter from Hogwarts, you learned that it was perfectly normal for wizarding children to have spontaneous bursts of magic. You and Ernie were placed in different houses, and he made new friends while you had almost none, and you basically stopped communicating

It was in your fifth year, after the first Dumbledore's Army meeting at the Hog's Head, and you were leaving when Ernie stopped next to you.

Ernie: Hey, I didn't know you were invited too.

You opened your mouth to reply, but Susan cut you off by running up to Ernie and tugging on his elbow, causing him to wince and shake his arm slightly

Ernie: I'll catch up, Susan.

Susan reluctantly stepped back, glared at you, but walked forward.

Ernie: Want to walk with me? We could go to the Three Broomsticks instead of that Merlin-forsaken place.