And it quite honestly isn't one of my favorite tropes.
My problems with the trope in romance are two-fold:
1. Regret is a waste of time.
In Sense & Sensibility, Willoughby regrets his choice to marry for money rather than love. Eleanor reflects that he would have regretted marrying for love if he'd actually done so. His regrets are the regrets of people who create utopias: the idea or expectation that life choices can be moved around a person's life like pieces on a chessboard rather than as organic events that arise from experience and lead to the next experience.
Joe versus The Volcano is the reality: "It's a long, crooked road that brought me here to you." People can make new choices but they can't unwind the road. They go forward from where they are.
2. People do move on.
There's a rather unexpected NCIS episode in which a woman comes to the United States to track down her husband. She is absolutely sure that he is still waiting, unmarried, endlessly hopeful of their reunion.
When the team find him, he is married. He isn't a bad guy (and the writers give him the excuse that he thought the wife was dead). It's been several years. He moved on.
Despite my problems with the trope in romance, I am a fan of the implicit grace of the trope. Combine religion and romance and one gets the fantastic ending of Babette's Feast. It isn't so much that one gets to rewind. In the end, everything is granted one. We don't have to bargain with God.
