Sheldon's mother, Mary Cooper, stops by for a visit before embarking on a Christian based cruise. Sheldon is excited about her visit if only to have his Mommy do Mommy things for him, like cook and clean. His expectations are even higher as he wants specific foods and wants to do specific things with her. But Mary seems to spend as much of her energies helping Sheldon's friends as she does Sheldon, if not more. She even refuses to hang out with him doing the things he wants to do - specifically go to a lecture given by a Nobel laureate just so that he can debunk his theories publicly - instead doing what she wants to do, such as typical Mary Cooper styled Hollywood sightseeing. Amy provides some insight into what Sheldon is going through, which doesn't make him very happy. But he unwittingly gets what he wants by being "common".