Lyric discussion by he4gives 

Cover art for What Can I Say lyrics by Carrie Underwood

I completely agree, however there is one thing i don't understand. The bsong says, "i'm not sorry that it's over." If neither one is sorry then why do they have a heart full of regret? If you're glad it's over you think they would be able to move on.

@he4gives it means that when they broke up obviously they were both heart broken, maybe they loved each other. But they know that relationship was not gonna work out in the end and are over the heart break