Hidden Wisdom is a Paladin spell card (rarity: epic) that belongs to the "The Witchwood" set, which was released on 12.04.2018 and is one of initially 135 cards. The artist of this card was Daria Tuzova, who also made 16 other artworks for Hearthstone.
The card costs 1 mana and its card text reads: "Secret: After your opponent plays three cards in a turn, draw 2 cards."
The flavor text of the card is the following: Find your own wisdom. Perhaps behind the couch.
Based on 105 quiz answers, the card is easy to memorize: 94% of them were correct. The question on “Card text” is answered correctly most often (100%), the one on “Name” least often (86%). An answer takes 10.4 seconds on average. In the Pixel Quiz, which shows only the shape and colour of the card, it was recognised correctly 71% of the time.