The meaning is quite obvious. He is saying that he loves this girl and he knows that that is out of his character and all his friends won't understand it. This girl means a lot to him and he has felt this way for a while.

"Even wrote the song Dreams for ya
Cuz I had dreams for ya
Even thoughts of a ring for ya.."
He wrote a love song for her because that is the way he felt and still feels. He wants to be with her and he loves her so much he would marry her and keep her for his entire life.

My boyfriend and I were choosing a song to be "our song" last night and this was one of my suggestions. It wasn't what we ended up picking but I like it a lot and wouldn't hesitate to change our decision to this lovely sweet song. My boyfriend also likes this song a lot.