There is no excuse why a confused and disoriented man such as Ahmadinejad should deny the holocaust.
Now here's the funny part. He says he's "proud" of his claim too. Proud of what exactly? Of his ignorance? Of the proof that his education was an absolute failure? Of the fact that he just verified, for everyone, that he is incapable of being a good leader? Of the fact that he is a laughingstock? Of the fact that a pig could better run his country than he can? Is that was he's proud of? It certainly must be because anyone foolish enough to embarrass himself like that to the world has proven this.