Did anyone regret leaving?

Has anyone ever ended a relationship because you could clearly picture your future with that person and it made you feel... unhappy?

Not because they were a bad partner. Not because you didn't love them. But because no matter how hard you tried to make it work you just couldn't see yourself living that life five years from now.

Did you ever regret leaving? Or was choosing the uncertainty of being alone still the better decision in the end?

I'd genuinely love to hear your story.