If You Want - Believe It, If You Want - Don't(1964)

If You Want - Believe It, If You Want - Don't is a Soviet comedy about three fathers on a peculiar quest. Roman Kurykin, a jazz musician with perfect pitch, cannot accept that his son Edik shows no musical talent. Convinced the boy was switched at birth in the maternity hospital, Kurykin tracks down two other families with sons born on the same day. He recruits their fathers, Shulgin and Sazonov, into his investigation. The three men secretly pursue their suspicions without telling their wives, leading to a series of misadventures as they attempt to uncover the truth. The film balances absurdist humor with the tension between parental expectation and acceptance, exploring what happens when fathers refuse to believe their children might simply be different from them.