Gilligan's Island S01 E35 My Fair Gilligan

"A three-hour tour"

After Gilligan saves Mrs. Howell's life, Mr. Howell decides to make him his son. He immediately puts Gilligan through basic training to be a millionaire's socialite son (dream sequence), changing the way he walks, talks and dresses. However, Gilligan and the rest of the castaways miss the "old Gilligan."