How is this supposed to work?

Hello everyone,
I just had a question. I understand why the no contact rule works in the theory. But how is it supposed to work? I mean, since the breakup I am healing and I start to get over the relationship. But isn’t my ex girlfriend feeling the same way? Isn’t she going to get over it, just like I am getting over it? Isn’t she feeling the same way I am, as time goes by? So how can it work, if she just moves on, and gets used to the way how things are right now? Or will the dumper feel later the same way the dumpee did? Or how does it work..?