A pro-baseball pitcher sends a curve ball to his opponent while many fans relax and enjoy the game.
A man is juggling baseballs while fans look on upset
one can not send a curve ball and juggle, one can not enjoy and be upset
The fans can't be relaxed and upset.
One cannot send a curve ball and be juggling baseballs at the same time. Fans would not be upset if they are relaxed and enjoying the game.