A two year old's discovery

I have been. . . kind of potty training my two year old. Yesterday he was sitting on the toilet to go to the bathroom. He started feeling his bottom, then he gasped and said;

"Mom! There is a hole in my bum!"

I took a few minutes to explain a little bit about digestion and human anatomy. . . with a smile. He is still pretty amazed that he has a hole in his bottom.