Sarah Green, a 62-year-old matron, returns to college to become more educated and sociable. During her first day of college, "Mrs. G" discovers that she has a lot to learn--and a lot to contribute.
Everyone leaves campus on Sunday. Mrs. G's Sunday plans to visit her family are spoiled when her son-in-law's mother becomes ill. She wanders the campus looking for someone to share her Sunday leg of lamb.
Mrs. G discovers that Professor Crayton had a secret love with a poet many years ago. She arranges a poetry-reading with the poet so he can meet up with her again.
Mrs. G is about to flunk chemistry, taught by nasty Professor Kestner (Peter Lorre), who even urges her to drop out, but her advisor Professor Crayton (Cedric Hardwicke) bucks her up and encourages her to give it the old college try.
Mrs. G begins to teach a free informal class in Western Civilization to her working-class neighbors, but she becomes so involved in this project that she starts to neglect her own college coursework.
Maxine is considering selling the boarding-house to a developer to pay off all her bills. It will put all of the students out, and Mrs. G will not have anywhere to go, so she invests her savings in half-ownership of the campus boarding-house.
Due to shortage of funds to run the boarding-house, Mrs. G decides to raise money by serving Sunday Dinner. Many students do not want to attend because of a certain boarder. How will Mrs. G get over this hurdle?
Paul (Fabian) wants to join the Peace Corps against his father's wishes, and Mrs. G, Maxie, and Professor Crayton all try to convince Mr. Volk to allow him to join.