[Armin knows Eren, so he isn't surprised or really bothered by the lip he is getting. He is asking Eren to believe something that would be completely ridiculous in any other situation. And Eren must have only just arrived here, so he doesn't even have the benefit of knowing this world.

So Armin closes his eyes for a moment, thinking back. The memories are old at this point, more than a decade in the past, but there are certain things that stand out.]

The first time we met was by the river. I was crying cause I just had gotten beaten up again. I remember you peeking out from behind a wall and asking me why I didn't fight back. We'd never spoken before, but I did know you were Dr Yeager's son.

You were still wearing your scarf too back then; it was before you met Mikasa, after all.

Anyway, you asked me why I didn't fight back, and I was gonna keep losing if I didn't. And I told you that I wasn't losing because I wasn't running away. That's when you asked for my name and we became friends. You were my first friend.

[He's smiling now.]

Grandpa was so glad I finally made a friend. And I know Miss Carla was happy too, cause you had never made a friend before either.