There really aren't too many flaws in human thought that bother me more than hard headedness. Hard heads PISS ME OFF. Not because they don't or won't listen to what I have to say. No. It's because they do the same thing over and over again without learning anything, thus doomed to repeat the cycle until something so catastrophic happens that they have no choice but to change their ways. Technically speaking these people are insane because they are doing the same thing over and over again and expecting a different result. To make matters worse, said people also like to drag other people into their insanity by having the same problem and needing the same advice for the same problem or needing the same kind of help because of the same problem.
Honestly, I really wish hard headed people would learn how to take advice. It's OK to not know everything all of the time, and sometimes it's best to let someone else do it for you and learn from them. Sure, your ego will take a hit but at least you won't be an idiot...