Dreaming about my ex???? :O?

So I've been dreaming about my ex? And me and him don't talk anymore like its all in the past he's happy with someone else I am happy too just going to school have my job etc but I don't get why I have been dreaming about him this Is the third time? What the heck? I am 1000% sure I don't like him nor love him its like all in the past he went on with his life I did too! It's just so weird! :|