"I tell you what, I was so shocked because I didn't think the ball had enough to get out. It's an absolutely incredible feeling. I can honestly say I did it"

Mark McGwire was clearly surprised and excited by his accomplishment. He was surprised that the ball had enough power to get out, which implies that he was not anticipating it to happen. His surprise and delight is evident in his words, as he expresses his amazement at the outcome. He is so proud of himself that he can honestly say he did it. His interest is contagious, and it is clear that he is feeling an incredible sense of accomplishment. His words reveal that he takes pride in himself and his achievement, and that he is still in wonder of what he has done. His enthusiasm and pride are motivating, and it is clear that he is feeling a fantastic sense of satisfaction.