Few people know that Mark Twain was interested in memory systems.

He even wrote an article in 1899, which was published posthumously in Harper's Monthly Magazine, called How To Make History Dates Stick. In this article, Twain describes his version of what is known today as the Loci system, and uses the reigns of English monarchs to show how it works. If you read it yourself, you'll be amazed at how easily you can pick up almost 500 years of history.

Towards the same end, he also developed Mark Twain's Memory Builder Game. The idea of this game was to play it regularly enough that you and your friends and family would retain important dates in history. Interestingly, the game divides historical events into three types - Accessions (Kings, Presidents and other heads of state), Battles and "Minor Events". Minor Events were considered to be any historical dates that didn't fit the first two categories. Is it me, or does it seem strange to consider things like the ratification of the U.S. Constitution or the Great Depression to be "Minor Events"?