Bet you didn't know THAT about Mr. Twain! Famed for titles like Huckleberry Finn and Tom Sawyer, perhaps it's not surprising that other less succesful endeavors by the author aren't as well publicized.
In 1883, Twain set out to facilitate his daughter's education by turning it into a game called 'Memory-Builder'. So really, we're talking about ye olde Brain Age, if not an early instance of gamification right here. The venture was succesful, and the girls memorized dates and names they were having trouble for months.
By now you're probably impressed and may want to try out the game, but the thing is, Memory-Builder doesn't look like the most welcoming of board games.The game board, as one critic puts it, "looked like a cross between an income tax form and a table of logarithms." Unsurprisingly then, despite efforts by Clemens to market the game to the wider public, Memory-Builder never caught on.
Still, if you're a masochist or perhaps just a big Mark Twain fan, you can learn how to play the game right here.