Grown up?

I turned 18 and thought I was grown
Moved away to live on my own
I was having fun and living my life
But when mistakes were made
it hurt like a knife
I thought this guy was gonna be right
But as it turned out, it was just that night
Then I thought, Maybe this one will be mine
but realized again it was just a good time
And now I'm waiting on the test
sitting here hoping for the best
and when I hear if it's good or bad
It will change the life, I once had