premise: János Gálvölgyi (born 26 May 1948) is a Hungarian actor and comedian. First appearing in 1968's Ki Mit Tud? talent show, he gained national fame for making numerous comedy sketches in the Hungarian National Television, becoming one of the best known comedy actors in the country.
hypothesis: János Gálvölgyi first appeared on a talent show twenty years after the year he was born.
reason: He was born in 1948 and then first appeared on the talent show in 1968, twenty years after 1948.