"The only thing I have never done is a Broadway play. I'm not sure I have the discipline necessary to do a Broadway play. I know it holds a fascination for certain actors"

Bob Newhart is revealing his admiration for actors who have the discipline to perform in a Broadway play. He acknowledges that Broadway plays hold a certain fascination for particular actors, but he is uncertain if he has the discipline necessary to do a Broadway play himself. This quote shows Bob Newhart's humility and respect for the craft of acting. He knows the effort and commitment that goes into performing in a Broadway play, and he is uncertain if he has the same level of dedication. Bob Newhart's quote is a testament to the commitment and ability required to be a successful actor. It also shows his respect for the craft and his adoration for those who have the discipline to take on such a demanding role.