The Past

Why is it that we go through experiences that we are meant to learn and grow from and then just let them hold us back later in life? When it comes to love we hold on to so much... is that because we dont want to be okay with giving up on the past relationship? Is it because we have a innate need to feel the rejection we went through was not because of us and if we get the past back we will know we were not being rejected? Is it beacuse we think it is not okay to allow ourselves to have those feelings for someone else and be happy, or is it simply that the new situtaion we are in is not what Heavenly Father wants for us?
I have gone through a lot of heart ache over the past year, thinking I had what was right, what was complete happiness and peace for me and then loosing it. I felt so sure that it was right and then it was gone. I dont regret the experience at all because I think that not every one ever gets to be that happy during their lives and I was blessed with the chance to have it for a moment. I have since realized that what I felt wiht this person in all reality had and has no chance of working out, in fact we would drive each other crazy, then why in my new relationships do I hold onto so much of the past and not just let the relationship grow and develop. I am scared of not being able to trust my own feelings. I think it is ironic that when we have expereiences good or bad and we try to better ourselves from them, that sometimes all we do is wind up huring ourselves more because we cant let go of the idea of them and let ourselves see what the next new adventure brings weither it is something that will work out or it is something that we will have another life lesson from. This is exactally why singlehood has its benifits, no need to worry about and stress over any of this stuff when you are not in a relationship. Then again there is nothing more gratifying or rewarding than discovering who we are, who someone else is and being able to share that with each other.