text: It would be helpful to know the why's of the break-up. It is possible that she is trying to make you believe that she is happier now than when you were dating, but whether or not it's an act would be hard to know. However it should be noted that IF she had forgotten you, she certainly wouldn't be looking back at you as she left class, now would she? What you did in the past is just that, in the past. It's what you do now, in the present that she's going to notice. If the break-up wasn't due to misbehavior or drugs/alcohol, it would be worth trying to simply talk to her. Whether via e-mail or in person. Just a simple " So how is everything going?" would at least start things off. Good luck.