Parting is painful

Parting for all of us is most of the times, 'painful'. But has any of you felt a little bit of pain when someone whom you really didn't like or someone with whom you really didn't click, left you and went away? When he/she was with you, you really didnt care about his/her presence. But his absence is bothering you. Maybe only momentarily, but it is.
Same thing happened to me today. I felt that pain, a little trickle of emotion in my heart, a faint sense of sorrow. We spent around 2 months together, most of the times arguing on our different perceptions for things, our conflicting choices and on hundred other issues. I didn't 'liked' him as such and many of his habits pestered me to frustration. But inspite of all this i never developed any sense of hatred.
Today he left & maybe I wont be meeting him again, ever. Cauz, maybe both of us wont take the pain to contact each other when we are in the same city. But his departure made my heart heavy. For a moment i wished that he wont go or that he may come back soon. But i knew, that wont happen. I am repeatedly reminded of him since morning & that feels very weird.
Maybe we dont realize that we will miss someone, untill they are gone.