The world is in the midst of a decades-long love affair with America's last true blue rock band: the Foo Fighters. Well, specifically, we're in love with the Foo's frontman, the gold standard of rock n' roll purists, Dave Grohl. And as our love grows (Grohls?) we become inundated with more and more stories about the cool things Dave and his merry band of Fighters do that give us the warm fuzzies all over again. So, by now, you probably know that Dave Grohl finished a concert in Sweden after falling off the stage and breaking his leg. And that he gets asked to record with everyone from Tenacious D to Zac Brown. And that the Foo Fighters are one of the most unsinkable bands of this or any other generation. But don't get too arrogant in your Foo knowledge just yet. Because even the most straightforward, hearts-on-their-sleeves rock band might still have a few ways to surprise you. For instance...