We often think that the only way to deal with an intellectual or emotional situation is to be very, very serious. When we are sufficiently tense, we know that we are focused. When we are one hundred percent committed, we know that we are doing everything in our power to come to grips with difficulty.
Well, almost everything.
I was once a soccer player. Soccer is a contact sport. It's important to be able to take a fair hit and stay on your feet and ready for action. If you are one hundred percent committed and one hundred percent tense, you are likely to end up with one hundred percent of your bum on the ground. If you want to take the hit and keep moving, you need to be relaxed, ready, and flexible.