Dárek(1979)

Everyone says he is incorrigible... Little Robert is an only child who has everything, he needed to be responsible for something, to take care of something. At least that's what the roommate of the apartment building where Robert lives thought, and sent him a live guinea pig by mail. The guinea pig gets lost in the apartment and Robert, to the amazement of his parents, studies books about animals and is sad that he lost the guinea pig. Imagine the astonishment of his father and his colleagues from the design studio when the father finds the guinea pig in his briefcase...