All teshuvah is thus a rewriting of the world and of history.
More than just redoing yesterday, we must change yesterday itself, the day before yesterday, the past year, and the year that preceded it by thirty years.
What was done will be as not done, and what was not done will be as done.
That is the paradox, the wonder of teshuvah:
A person can change the course of his life not only prospectively through resolutions for the future, but also retroactively.
–Rabbi Adin Steinsaltz