Firstly, you wish the person never existed, and the memories to burn to ashes. 

Secondly, you hate the person and the memories you had with them. 

Thirdly, you’re indifferent towards the person but you’re nostalgic for those memories. 

And lastly, when a high level of inner peace and calmness is reached, you smile remembering those memories and how happy you were at that time, with no thoughts of the person in mind. 

That how you move on.