it took me no more than 3 physics classes to master that. The one where I spin a pen around my thumb then catch it again. There are several other variations that I cannot do. I have also mastered spinning anything from frisbees to notebooks to my laptop on one finger and keeping them spinning for as long as I desire. I can also bounce a golf ball on a sand wedge for about 20 minutes. God, i have wasted a lot of my life practicing useless talents.