Its a million dollar question that "Can anyone move over his/her X? " and its very common reply "Yes" with time the wounds healed up. Really? Is it simple to move over or forget a time period from time line of your life and enjoy rest of the life with nothing really happened. Things get changed, emotions and behaviors get changed due to the pain and bad experiences. We do look new people keeping past experience, then how one could say that he/she moved on over his/her past? This is the way we learn from our pasts. Correct our wrong doing and do stuff to avoid previous experiences.
I think, its not possible or logical. In any stage of life, we do remember those who betray us or hurt us in any way. Indeed, we may lost the pain and connection with the Mr./Ms X but its not moving over but it is simply "out of sight, out of mind" thing. Change in environment, change in social circle and even change in routine life may effect your relationships and could change your best friends. Long distance relationships are good example of this.
The only answer of this is to accept your mistakes and admit the past and keep it with you with open heart and mind. its human nature that we not accept our mistakes easily and quickly. We keep making excuses for our mistakes. This not resolve anything and we keep trying to undo and go back to the point where things started.
We try to find escape ways for ourselves not to admit the issues and past failures. Being or continue as friend is one of those escape routes. Friendship is a relationship in which a person trust another being, share feelings and enjoy/grief together. Here is the question. Do a person betray u or hurt you can remain eligible to be your friend? Will you able to share your feeling and enjoy happy moments with him/her when once you are hurt and your feelings were compromised upon anything? I think, the answer is "No". The truth is we are so much in our "Xs" that we want to them to feel like ourselves for them, but it is never be true because if this should be the case then they not left at first place. There is always a way to resolve issues and paths to compromise but when one decided to leave above being together then how he/she can feel same as you do?
Thus, the logical and better way to get over a breakup is to accept it and analyze selves, not to repeat mistakes and show our weaknesses again. Blind trust, assumptions and keep hope for better response hurt things. Its better to discuss things with partner and share reservations at the right time instead keep them in heart. Keeping self respect and protected boundary for selves, so that no one cross these boundaries and if one do, we aware of our course of actions to realize him/her that it is not fair and unacceptable.
If Love is for-giveness then it should be from both ends not one sided game...
you are welcome to disagree and prove me wrong...