Fast forward all the way to the last paragraph: Macy and Wes are jogging on the beach in the morning sunshine, truly together at last.
But wait a second. Do you remember how Macy's dad died? That's right: jogging. It looks like Macy has finally learned how to mourn her dad—instead of pushing aside all the things he loved (like running), she's embracing them.
We think the scene itself isn't nearly as important as the thoughts passing through Macy's head at the time. She has finally realized that she has the power to choose her "forever," and she has claimed that power, changing her life for the better:
There was only one truth about forever that really mattered, and that was this: it was happening. Right then, as I ran with Wes into that bright sun, and every moment afterwards. Look, there. Now. Now. Now. (22.29)
Changing your forever isn't some future event, far off in the distance—it's something you have to do right now: because forever is now.