How do you know when it's "the one"?

6th grade I had my first real crush... I'm just going to call her A. I didn't even know she existed until in 5th grade she played a part in the 5th grade musical... Anyways, in 6th grade she was in my class and the moment I saw her... She just... I don't know. She was perfect. Personality, looks. Even to this day, she is one of the nicest people I have ever met. She was an angel. That was my first impression, angel. She was the closest definition to perfect possible. I would of spent my life with her. I wanted to spend forever with her... I liked her for 2 years. And my friends convinced me to ask her out at the end of first quarter in 8th grade. She said no. And looking back, it was love at first sight. From the moment I saw her in the 5th grade musical, I loved her. Don't say it wasn't love because I can't love at that age, because it was. I was in love with her. And she said no... The girl of my dreams. The girl I thought was "the one" wasn't. Did I screw things up with my one? Will I never love someone as much as I loved her again? Will I spend my life with someone who pales in comparison? I can't think right now. Help... Was she the one? Is there no one for me? Thanks