Neglected women are easy targets for players and other men. Usually by the time the girl tells you ... it is too late.
Women are careful creatures and they will put safety nets in place before they let go of your arm.
They will, for example, have a couple of new guy friends to chat with on the phone, and start going out to clubs a little, and then tell you it is too late it is over...and it wont hurt them as bad, because they are braced for the fall.
Learn what you can from this and prevent it in the future, but if she leaves you without giving you an opportunity to make it right, she is not the right one.