The movie follows the story of John Farley, a successful self-help author who teaches people how to conquer their fears. John's life is turned upside down when he learns that his mother, Beverly, is getting married to his old high school gym teacher, Mr. Woodcock.
John despises Mr. Woodcock, who was a cruel and sadistic gym teacher during John's high school days. Mr. Woodcock made John's life a living hell and traumatized him through constant ridicule and bullying.
Determined to stop his mother from marrying Mr. Woodcock, John returns to his hometown and tries to persuade her to break off the engagement. However, Beverly refuses to listen to her son's warnings and tells him to let go of his grudge against Mr. Woodcock.
As the wedding approaches, John and Mr. Woodcock engage in a series of hilarious pranks and stunts to outdo each other and prove who is the best man for Beverly. In the end, John learns to confront his fears and stand up to his old nemesis, leading to a hilarious confrontation at the wedding.
The movie stars Billy Bob Thornton as Mr. Woodcock, Seann William Scott as John Farley, and Susan Sarandon as Beverly Farley. It is a comedy that explores themes of overcoming fear, the power of resilience, and the importance of forgiveness.