Article on NPR: Why It's Hard to Admit to Being Wrong
The article explains why people often value something more if they had to go through a lot of pain to get it: it is often too hard to accept that the pain might have been meaningless.
This explains to me why some parents make their kids go through things that were very painful for themselves (some aspects of school come to mind). They believe that in the end, it was worth it. Mind you: that may well be true, but the kicker is that they believe this because of the painful experiences and not despite them.