The film describes an adult who turns out to be totally unsuited to an independent life. He cannot write a letter to his mother, whom he dreams so much of finding, is unable to settle accounts with the seller in the store ... At 20, Pyotr Kasikhin does not know the alphabet, and the tasks elementary children with birds sitting on a branch seem incomprehensible. No, he's not the fool many think he is. He once went to a mental boarding school. And, it seems, by mistake, Peter was diagnosed as "untouchable", he was not sent to school ... Despite everything, Peter, who has already matured for a long time, goes to first grade ... The others are laughing!