The movie establishes that Juan (Karra Elejalde) suffers Korsakoff Syndrome. It is a real-life disease which affects to the memory and the cognitive process, specially in cases where the patient abused of drugs and alcohol. The affected by the Syndrome have memory loss and mental gaps, filling the lost memories with those that they see around them. It was firstly documented by Russian Sergei Korsakoff, a prominent doctor who wrote about forensic medicine, neuropathology and psychiatry (being also who introduced the concept of paranoia), and that in the late 19th century reported about the alcoholic psychosis and how the memory was affected by the abuse of substances, mainly drugs and alcohol.
Actor and comedian Iñaki Urrutia makes a cameo playing a living statue in Bilbao streets, disguised as writer Miguel de Unamuno. Karra Elejalde played Unamuno in the movie Lettera a Franco (2019).