We've always thought we were pretty knowledgeable where history is concerned. Hell, we could write a book about history memes. We thought we were experts, but now, thanks to one Tumblr thread, we've been properly humbled. This selection of Tumblr posts takes historical notions we took for granted and flips 'em on their head. We're still shook after realizing that Tiffany is a name from the eleventh century. You really do learn something new every day.