Taylor Swift - Forever & Always Lyrics Meaning

I don't know if it's about Joe Jonas, never heard that one I'll have to google it lol ;) anyway, I always thought it was about a typical girl, and things seem fine with her bf until promises are broken, walls are built between the two as the akward silence continues, phone calls go un-answered, etc...
I might be wrong about the song meaning, I just like this song b/c it relates perfectly to me & my ex. Peace out peeps :)