I haven't read further than I think the Gaara rescue arc, but the impression I've gotten is that like Calvin, he's a mix of very bright and a complete idiot ("How can kids know so much and still be so dumb?"), that he thinks best under pressure, and that he spent way too much time growing up focusing on getting people to like or at least notice him, which can be attributed to upbringing. (Of course, it then becomes self-perpetuating -- people stop disliking him on general principle and start disliking him because he's an obnoxious loudmouth brat. It wasn't so much that Iruka gave Naruto a chance as it was that he kept expecting better and saying "Yes, but...")
As for the sabotage theory... eh, I blame Viridian.
Pronounced "shy guy."
As for the sabotage theory... eh, I blame Viridian.
Pronounced "shy guy."