Le clochard milliardaire (1951)

Olivier Cabrol is an immature young reveler who lives from hand to mouth. One day he inherits a fabulous fortune from an eccentric uncle. But on the one condition to spend a certain amount of time as a tramp. Olivier accepts out of sheer greed but soon finds the experience rewarding. He finds himself as well as new friends (true ones this time) and even love in the person of Colette.