This is a video of some cat (a dude, not an actual kitty) playing the Mario theme on a piano one handed. That's one hand less than the regular amount! Now if he could play it with nothing but his head, THAT would be something. Which, true story: one time I filmed myself played FÃ¼r Elise with my face but the piano exploded with awesome and destroyed the video camera. But you can take my word for it, I'm honest.
Thanks to naas and Rafi, who can both play the Mario theme simply by willing it with their minds. It's called The Force, guys.