Janos Bán (Who played Otík) had almost no comprehension of the Czech language (As he is Hungarian) and had to therefore learn all his lines phonetically. His lack of comprehension of the Czech language also allowed him to portray his character as a mentally deficient village idiot far more convincingly than a native Czech speaker ever could.
The film was made basically by accident. During a review of the archive in the Barrandov Studios, it was discovered that the story for the film Na samote u lesa (1976) was paid to Zdenek Sverák twice by mistake. Barrandov suggested to Sverák that he should write a few pages of some other story by the next day, which would be put away among the rejected ones, and the reimbursed amount would find its destination. A few weeks later, the draft was in the hands of Jirí Menzel and the decision was made to make the film.
The only film in which three Rudolfs from the Hrusínsky family appeared. In addition to Rudolf Hrusínský, who played the doctor, his son Rudolf Hrusínský as Drápalík and his grandson Rudolf Hrusínský as the young man who goes to watch TV "when they set up the mirror".
The doctor played by Rudolf Hrusínský recommends the patient played by Jirí Lír to visit Pelhrimov. Jirí Lír was born in Pelhrimov.