Why?

Why is it when someone posts a topic that others wish that they did not, do they keep posting to the thread hoping it will go away? They even say sorry or antagonize people to keep it going,
Baffles me to understand, I guess I figure if you ignore some things they will go away, but posting that in one that you wish to stop, keeps it going.
Feel free to bump to blank out those you wish to stop.
Cheers