Martin and the Wizard (1979)

Martijn receives little attention from his parents, who run a village bazaar, and is often left to his own devices. He has plenty of imagination, but cannot live up to the expectations placed on him. If he fails his school exams, he will be doomed. Only his grandfather in the retirement home understands him and listens to his stories. When a film crew arrives in his hometown to shoot a fairy tale movie, Martijn is chosen for the lead role and his grandfather is given the role of wizard.