The same damn question over and over again.

Why do some people do this? Keep on and on and on, the same damn question over and over again, like repeating themselves up to 10 times!
There are some, a sane few, who just ask a question once, debate and engage with the rest of us and move on.
Sadly, there are too few of them here, the majority just harp on forever and it gets wearisome.