Brewster's Millions (1945)

Monty Brewster is a penniless, former U.S. Army soldier back from World War II Europe who learns that he has inherited $8 million from a distant relative, but there's a catch: he must spend $1 million of that money in less than two months before his 30th birthday in order to inherit the rest. Since he cannot tell anyone about spending the money as part of the agreement, everyone thinks that Brewster has flipped when he practically knocks himself out on a spending spree to get rid of the $1 million in time.