There is no denying Lebron's physical talent. He is one of the most (if not THE most) talented people to ever play the game. That being said, he does not have the mental edge to become the best basketball player of all time. He is too concerned with whether people like him, letting his teammates down, etc. He has even said that when he loses, he feels awful because he feels he let his teammates down. But as a competitor, you should hate losing because it sucks. Winning/losing isn't about pleasing other people. The drive to succeed has to come from within. This is part of the reason people doubt that Lebron will ever become someone who can consistently close out games and be counted on to hit the big shot.