This will boggle your mind...... And it will keep you trying over and over again to see if you can outsmart your foot.
1). Without anyone watching you (they will think you are GOOFY....) and while sitting at your desk in front of your computer (or where ever you can sit), lift your right foot off the floor and make clockwise circles.
2). Now, while doing this, draw the number '6' in the air with your right hand.
Totally weird phenomenon.
Thanks to my mother-in-law for this one!!