Strange dream about someone from my school

I can’t seem to understand this dream I had last night,I was wondering if someone could help me.

It has a few people in it, but I’m not going to use their real names.

I’ll give some info about me and the characters in it: The main character in my dream is someone who goes to my school (we‘re both in the same grade). Let’s say his name is John. I talk to John sometimes, but I haven’t for a while because I don’t see him often. I used to sort of have a crush on him a while ago, but I would just ignore my feelings, even now I still ignore it and try not to think about him, which is much easier now because I hardly see him at all.
During this dream, I’m at my grandparent’s house, (which I go to often Because I like visiting them.) John lives right across the street from my grandparents. He has two sisters, Who are twins. we’ll call them Jen and Liz. I’m about 4 years older than Jen and Liz. They are really fun to talk to, but again, I never see them.
Okay here’s the dream:
It started out with me walking down the hallway of my school. The hall was crowded, like it usually is when we switch classes. I see John walking down the hallway. Suddenly my friend comes over to me and says “John is a hero.” I became very confused,
“Why, what did he do,” I asked my friend. But she wouldn’t answer me.
So I start walking to my class, but I was just too confused I had to find out why John was a hero. Instead of walking to the class I was suppose to go to, I walk into my favorite teacher’s class, hoping that she can explain to me, why.
As I walk into her class I feel guilty, as if I’m in trouble for skipping my real class, but I ignore that feeling and stay. “Why is John a hero?” I ask my teacher.
I can’t recall exactly what she said, But I know she said something like this, “Because he is, John is a hero.” She wouldn’t even tell me why.
So I ride the bus after school to my grandparent’s house. I see Jen walking along the street by her house, Everything, including Jen’s house looked just the same as it always did. I quickly run up to her and say hi. Jen says hi back, she also introduces me to her friend, who had been walking next to her. Jen’s friend strangely looked a lot like Liz, her twin sister.
Later, I walk into my grandparent’s house, and ask them, “Why is John a hero?”
They answer me, “Didn’t you know, his house burned down the other day, he ran back into the burning house just to save his sister Liz. But she died anyway.” My grandparents said that as if John had done the most amazing heroic deed, but there was also a very serious tone in their voices. I was instantly saddened, about Liz’s death. I pictured John carrying her out of his burning house, and her being dead. Then I woke up.