In Act 5, Macbeth's attitude while entering the war was of supreme confidence. He was completely certain that he was already victorious and had no qualms about losing whatsoever. He had this attitude because of the way he interpreted the witches second set of prophecies for him, and in reality this attitude in turned helped contribute to his defeat. Macbeth went into the battle thinking nothing could happen to him. He was not thinking clearly and this helped the enemy be able to easily defeat him and his arrogance. This inevitable defeat that was coming his way, finally opened up Macbeth's eyes and forced him to hear the truth of the matter but by then it was too late.
When entering the war, Macbeth was overly confident in his forces. He was very confident because he had recently gone to the witches to see what he should look out for and they told him to not fear anyone that came out of a woman's womb. He took this as he was invincible to everyone around him. The attitude he had made both Seyton and the Doctor in Act Five Scene Three see him as cocky. He was arrogant because he believed that he should have no fear in his heart. Macbeth's arrogance made him not prepare for what he had coming for him and hence his head was cut off by Macduff.