This theme is clearly shown in act Ⅲ when Emily goes and revisits the past.
When she does; so she returns to her 12th birthday where she shortly realizes that life was too rushed. Life was so rushed, in fact, that her mother never even looked upon her face.
I have also seen this theme in Tenth Avenue North's song "You Are More." In contrast to the book, however, this song claims, yes, you will have regrets, but through God, we are forgiven and are worth more than the compilation of our past mistakes.
It's true that we all have regrets. Humans are incapable of living perfect lives and there will always be mistakes made, whether big or small, however, I find personal hope and peace through Christ, who loves me regardless of my past mistakes.