Why do I constantly wonder about what could have been?

Because you are not focusing on where you are now. When you believe in yourself, your regrets will have less of a hold on you.

You are living in the past and often this feeling leaves levels of regret. Maybe you don't take life by the horns and don't do what you truly want to do. All I can say is maximize your opportunities and do thing that will genuinely make you happy, right this moment and maybe you will stop living with shoulda, coulda, wouldas!

Because deep down I feel as if I somehow failed and that I could have done better if I tried. And that maybe my life would be so much more better if I made better choices.

It's hard to let go of the past sometimes, because we like to think back on how it has shaped us for who we are today. That being said, past events are both good and bad and as human beings we are "cognitive misers". This means we take in so much information, that we can only remember a fragment of what has already happened. In other words, we end up focussing on only the good parts and so much the bad parts. However, I want you to think this: what you did back then was based on the information you had back then. Think of these as learning opportunities and not mistakes.

We always think about the "what if" possibilities, it's human nature. But you have to trust your path and take notice of where it takes you and accomplish your goals regardless of anything. As long as you end up where you need to be, those "what if" s don't matter. If you are constantly tied to what could have been, you'll be less focused on what's going to be. You can't go back and change anything, but you can change your future and rebuild and grow. Don't lose hope, we all make mistakes and do things we wish we could change, but its part of learning and growing.

Wondering about future hypotheticals is fun sometimes, but it shouldn't be a habit. Are you dissatisfied with your current situation? That may be why you're thinking about those what-if's. Consider keeping a gratitude journal. 7cups offers one on their dashboard bar (I don't know the right term for it), where it says notes on the far right side. Just keep track of the little things you're grateful for each day and you'll find more contentment in your life.

Natural human instinct sadly :) Just try to focus on something else :)Everything will be ok regardless. Good luck!

I wonder because the break up is still fresh and hurting and I have nothing better to do. Time is a good healer, time will come when this would just seem hazy

It's natural to wonder that. It is maybe because all the choices you made, you always wonder what if you made the other choice? How would life be different? But to get past it, just move forward and think about the choices you make.

human nature is like that, almost everyone suffers from this. we allays want better and we don't realise how good we are doing or we think we can always to better then we do and we keep think about the mistakes or could have been and done, I think it helps us top push our self to do even better if something goes wrong, we sit their analysing the things so it is good in a way but we shouldn't be too harsh on ourself all the times.