>I hear this all the time. Even if something turned out horrible people say they would do it all over again the same way. Isn't that stupid? They wouldn't try and change anything to make it better?
In the US, there is a very strong cultural bias to denying that you've made *any* mistakes. That antipathy to admitting errors predates the "litigation crisis" while the current excuse is along the lines of "if you say you're sorry, you'll pay for it in court." And it comes with a double standard too: bush is "resolute" while you're "stubborn." Admit to wanting to do things differently? That makes you a flip-flopper. It goes along with a "cowboy" mentality. Or the parrot salesman.
In interviews, sometimes you'll be asked what you would do differently with your life, if you got to live it over again. That's a trick question. They're prying to determine if you're a complainer, or an intellectual. Any serious answer (such as to the question "what is your greatest weakness") is the wrong answer: you fail the interview. A reasonable non-answer for the interview-fu is "I'd have brushed my teeth more, so I wouldn't have gotten all those cavities." Admit that you'd have gone to a different school? Chosen a different career path? To most Americans that is equivalent to saying "I wish I was never born." Yes, I'd have done things differently, if I knew then what I know now. I'll never admit it publically.
People suck at self-evaluation.
People also suck at figuring out what went right and what went wrong. Simple techniques you learn in six sigma, tqm or other b-process-fads can and will help, because most of them are aimed at finding out what went right, so you can do more of that. And finding out what went wrong, so you can do less of that.
In the political realm, folks who wanted to understand why 911 happened, so as to prevent other similar events from happening were viciously attacked: "why do you hate America so?" Where the antilogical discourse became a porridge of "no true scotsman"  with the "dogmatic fallacy" .
 samples: no true red-blooded American would ever disagree that spreading democracy is wrong. No true American would ever disagree with gwb.
 samples: if you have evidence against iraqi WMD, then you are evil.
If you have evidence against iraqi wmd, then your evidence is false.
If gwb says that anyone who leaked Plame will no longer work in this administration. Libby claims cheney authorized the leak. Cheney is still VP. If you think that the truth applies to gwb, then you forget that truth does not apply to gwb by definition.
There are people still pissed off about the stand-off in Waco, Ruby Ridge, and the government's action. Not everyone in the US thinks McVeigh did wrong for taking revenge on the feds. When that guy stole the A-10 (had 500# bombs and a full load of DU ammo), and flew towards Denver, when/where McVeigh was on trial, was he heading there to free McVeigh, or was he heading there to bomb the courthouse to kill McVeigh? Was flying into the side of the mountain an act of remorse, an act of suicide or a navigational error?
Yes, it is stupid. But it is human nature.