Juggler

One ball, throw and catch, throw and catch
Two balls, throw one, catch one, at the same time, throw one, catch one, at the same time,
Three balls, throw one, leave one in the air, catch one, all at the same time, then again
Four balls, throw one, leave one, no two, in the air, catch one, no two, all at the same time, I can't
You need to master this craft.
I'm not the master.