All of these and more, because you realize that ,when all the smoke is cleared, you dated a complete and total dipshit? And not only that, that all your friends are in the cahoots about it and there's no backtracking on the fact? Saddened about all the inside jokes they've gotten the chance to stock up on that you'll hear about until the day you die (like the time he talked about how many dates he went on when you were at a group dinner and everyone's eyes bugged out, or how about when she made out with one of your friends in front of you at a bar right after you ended it)?
Don't let it get you down, sisters and brothers. If you're like me, you get up out of that bed of shame, you scarf down some yogurt, you brew a pot of coffee, give yourself an Annette Benning pep talk ala American Beauty, and you listen to your fancy under-cabinet mounted kitchen CD player while playing this fucking raging tune over and over and sing along until your landlord's ears bleed.
Enjoy OMD's So In Love. Possibly one of the world's best breakup songs.