DS Daily: A lesson learned
Also, if you assign each card a numeric value from one to thirteen (with an ace equaling one, a king equaling thirteen), they will add up to 364. That's why there are two jokers: One makes the year complete, since a year has 365 days, and the other is there because there's an extra day during leap years.
Are there any cool little facts you've learned from games that you've played? Maybe even something less trivial than the card fact above? Share them with us. This way, you'll have some ammo when people scold you about not learning anything from video games.