Nemtudomka (English: Little I Don't Know) is a Hungarian fairy tale, first published in the mid-19th century by author János Erdélyi. It is classified in the international Aarne-Thompson-Uther Index as ATU 314, "Goldener". It deals with a friendship between a king's son and a magic horse that are forced to flee for their lives due to the boy's own mother, and reach another kingdom, where the boy adopts another identity by only uttering the words "Nem tudom" ("I don't know").
Although it differs from variants wherein a hero acquires golden hair, its starting sequence (persecution by the hero's own mother) is considered by scholarship as an alternate opening to the same tale type.