To present another side: I remember from reading Chuck Yeager's autobiography that Neil Armstrong was also a bit cocky and "know-it-all". However, I cannot find a quote of the passage online.
It should be pointed out the Neil Armstrong was US Navy and Chuck Yeager was US Air Force, so there is a bit of inter service rivalry. Chuck Yeager did tweet '"Too bad we lost one of our good pioneers. Neil (Armstrong) was a good friend and we'll miss him" - General Chuck Yeager'. Yeager's comments seem to jive with a lot of others that Armstrong was a great engineer.
It kind of freaks me out that Chuck Yeager is still alive (89 and going strong). From The Right Stuff, he seems like he's from an earlier generation than the astronauts, but I guess he was roughly their contemporary.
Lets just skip over the NF-104 mishap?
Despite what people think, most of the astronauts/test pilots have done at least one not-so-smart thing in a jet. This was probably not Gen. Yeager's finest piloting. http://en.wikipedia.org/wiki/Lockheed_NF-104A#Third_NF-104A
Gen. Yeager was also somewhat bitter that he never made it into the Astronaut Corps.
IIRC (it was a long time ago) CY said he did not become an astronaut because he wanted to be a pilot and not just shot around on the end of a rocket. I took it at face value, not thinking that it might be sour grapes. Needless to say there was some amazing piloting in the Gemini and Apollo programs.
He didn't make Group 1/Group 2 requirements to the Astronaut Corps because he wasn't a college graduate. This was at a different time when not all officers had a 4-year college degree. He could have gotten a degree, if he really wanted to be an astronaut.
During the late 50s, the designers had the plan that the capsule would be flown automatically, and this could have turned off Gen. Yeager from applying, despite his distinguished record.
I'm not saying NA wasn't cocky or didn't get a jet stuck in the mud, but I find it interesting that CY's stories of the man seem so different than everyone else's.
Stories are generally told to reinforce someone's existing narrative. If you think someone is an idiot you will tend to tell stories of them looking foolish. If you think someone is brilliant, stories of them looking clever. All humans, if you looked at their sum-total of actions/decisions, could likely be equally well placed in either camp. Which stories are remembered/repeated is probably as much due to chance as desire for historical accuracy. Not many people, when they think of Newton, think of an alchemist.
This comment should probably be translated into 40 languages, cast in pure gold, and illuminated with spotlights in every major city of the world. Humans need 'stories about the world' to understand it, but we often forget that the stories - and our categorical abstractions in general - are a highly filtered and edited subset of reality.
I did find this interesting anecdote in which Neil Armstrong doesn't appear quite so clever: http://www.achievement.org/autodoc/page/yea0int-7