Yea Ellyn is right, it is more than likely you are not quite over your ex, was it a painful break up or something? Just if that's so then that may well be your answer. It may well be that you still have feelings for your ex, have a think about that one. There are also probably some little things about your ex which you liked more, though your ex may not have been as great if you look at the big picture, it is often the little things which we base relationships on.