Why does anyone leave a relationship

Because we should never leave a circumstance just to change the way we feel, at what point would we ever leave a relationship? Is it just because we like our reason? I recognize that when I think of my reasons, I can get to a place where I achieve my reasons without leaving. For example, I’ve never really been alone in my life. I’ve jumped from relationship to relationship. I’d like to find what I truly like. How I truly want to live my life. How I truly want to spend my days. I’d like to meet men and not feel that I need to automatically like them simply because they’ve shown some interest in me. I’d like to really take time to focus on what it is I truly like and get to know myself better. I realize that I can do all of these things and get to know myself better and find what I truly want and like while I stay married to my husband. So at what point does anyone ever leave a relationship if they can get to the feeling/action/result they want without changing the circumstance? In this moment, I recognize that I love my husband. He’s a good guy. He has many positive qualities. I don’t believe in having regrets in life- there is so much this marriage has given me that I’m grateful for. But if today I had to make a decision to marry him again, I would not. Can you help guide me in the next step to processing this information?