I guess it means that moving on usually requires leaving friends behind, and not that experience requires some kind of drama or even explicit un-friending. But the presentation makes it seem like losing friends causes gaining experience instead of the other way around.
"And 2 broken hearts to stop being a teenager? And the only way to get experience is by losing friends."
i'm not sure i directly relate to this either, but it really doesn't sound too crazy or unfamiliar.