Nora realizes that the life she abandoned—the "root life"—is not worthless. It is the one where she can still make a difference: to her neighbor, to the people she teaches, to herself. It is the one where she has the chance to want what she has instead of what she didn't do. The root life is the only life that is still open—because it is the one she is actually in.
In every other life Nora was living a version that had already branched. The root life is the one where she still has agency—where she can choose to stay, to reach out, to try. It is also the one where the people who need her (her neighbor, her students, the town) are. Leaving the root life was not an answer; it was an escape. The answer is to want the life she has.
Wanting is a skill. We can learn to want the life we have—not by pretending it’s perfect, but by seeing that it is enough to work with and that we are needed in it.