Nostalgia

I've been living with you all my life.
You were here when I was 13,
and I didn't know why I was alive.
You were when I was 15,
and I just lost my best friend, again.
You were here when I was 17,
and I started feeling scared again.
You were here when I was 19,
and I started feeling trapped in this life.
You are here now, I'm almost 21.
I wonder if you will ever go away.