Backstory:

My brother was in the same grade as me, before he dropped out
So the guys who are in my current class (this is the first and only year im mixed guys and girls) were in his class.
[In my culture and religious beliefs, this interaction is usually unexpected]

Interaction 1: I was talking to my friend during a class, the teacher was helping other students get a picture.
But me and my friend + this one guy weren't in it
So we were talking laughing, waiting for class to be over, I dont even notice him approaching, but he comes up and goes

"Excuse me, but was your brother in the school before?"

I've never spoken to much guys before, so Im like nervous, I made eyecontact once and then avoided it completely while I was replying.

ME: "Yeah he was, why?"
HIM: "What is he doing?"

I reply, and he goes thats really cool..

and then im like "Yeah"

and then thats it.. he walked away

Now I would like to know your opinions, what you think his reason was and anything and everything else.
Then I'll put the second interaction
Thank You! <3