If the fact that Glinda sings the alto part and Elphaba sings the soprano part in for good (because they’ve both taken from each other) in For Good doesn’t make you tear up a bit then I don’t know what does.
what she means:
One question haunts and hurts too much, too much to mention. Was I really seeking good or just seeking attention? Is that all good deeds are when looked at with an ice-cold eye? If that's all good deeds are maybe that's the reason why.