The song is written for her friend not her lover or whatever. It's a beautiful song, I guess. It's there to show that she is there for her friend and hates to watch him go through the pain especially when she knows what it feels like hence, "I hate to see your eyes get darker as they close/ But I've been there before" Or it could be seen in a different way. She could be saying that she has seen him in this love-lost state before and she hates to see him go through it again.
The song is written for her friend not her lover or whatever. It's a beautiful song, I guess. It's there to show that she is there for her friend and hates to watch him go through the pain especially when she knows what it feels like hence, "I hate to see your eyes get darker as they close/ But I've been there before" Or it could be seen in a different way. She could be saying that she has seen him in this love-lost state before and she hates to see him go through it again.