You've been through some tough times in your life. You've made some decisions you regret; done and said some things you wish you hadn't.
I don't need to know you personally to know this. One of the most important things I've learned in my life is that everyone has issues. Some peoples issues are big and showy, some peoples issues are easier to hide. But everyone has issues. And as such, everyone has been through some tough times. That's life.
But you know what can make those tough times even tougher?
Having an out you didn't take.
You know what I mean. The dark feels just that much darker when you know you had a way out, an opportunity to right the ship that you didn't take. Missing an out can magnify regret and lead to some serious second-guessing down the road. It makes tough times tougher.
And it can add darkness, depth, and a psychological edge to your story.
You character's in trouble, the world is crumbling around her. Then the realization hits, "None of this would have happened if I would have just given the wizard back his giraffe." (or whatever)
Now your character has something to torture herself with. She has regret. She has something to remember when the next big decision comes her way. Has she learned from her mistakes or will she repeat them? Can she even recognize the out when it looks her in the face?
Give your characters an out and then don't let them take it. They won't love you for it but your audience will.