Finality is not an easy thing. As a writer, all I ever think of is possibility. In my stories, I think about what could happen. If there is anything that can't happen, I think about ways where I could change reality itself to make the impossible possible.
Along those lines, I always think about editing. Any time I make a decision and decide it was not good, I could highlight it and press the delete key (pr tear out the page and throw it away. Whatever has happened, there is always a way to change it.
And even if I was in a situation where I could not change my decisions, I can always twist fate to make my characters do what I want.
This is one thing where writing and reality are quite different. Reality has a great deal of finality in it. It is not easy to make such choices, knowing that your choice cannot be unmade, but it is unavoidable.
That is why, when we are in such positions, the best thing to do is use all of your analytical and hypothesizing skills to figure out what the best choice to make is (much like Robert Frost did in that infamous yellow wood).