Who knew?! -- Share an interesting fact

Let's see if this catches on. [img:28343b52a6]http://www.afterellen.com/emoticons/whistle.gif[/img:28343b52a6] [b:28343b52a6]Background:[/b:28343b52a6] I'm always stumbling upon interesting facts that I never knew but are probably really obvious to other people. For example, today I learned that Washington D.C. (not a US state by the way) has a flag. I can't believe I grew up only a few hours from the District and I've never seen it before! [img:28343b52a6]http://www.flags.net/images/largeflags/UNST0150.GIF[/img:28343b52a6] So maybe we can share interesting bits of information with each other and learn a few things? This thread can also be used to enlighten each other on broad--but seemingly obvious--subjects; for example, had I not seen [i:28343b52a6]Hotel Rwanda[/i:28343b52a6], I'm ashamed to say I never would have known that genocide in Rwanda killed nearly a million people in the mid-90s. How my public school education evaded this subject completely I'll never know! So those are my two interesting facts for the day. [Though this thread may turn into something else, I'm technically referring to useful bits of information, not trivia or urban legends like, "Did you know that no U.S. President has ever had brown eyes," which is silly at best and probably not even true.] [b:28343b52a6]Instructions:[/b:28343b52a6] Post an interesting fact (not trivia, please) that you learned recently and couldn't believe you didn't already know. Commence sharing and learning. [img:28343b52a6]http://www.dandyandcompany.com/forums/images/smiles/smart.gif[/img:28343...