I have noticed from experience that taking things too seriously can be debilitating. It can paralyze us.
It is usually more effective to approach problems with a light heart – a willingness to laugh at them and at ourselves. Otherwise, if we are too somber, we could be stricken with a heart attack before we even have the chance to do anything to improve the situation! Instead, we can be playful. A sense of humor can be very helpful in preventing us from feeling stuck or overwhelmed by a difficult situation.
Especially if a situation is critical, you have to be able to approach it with some openness, just in order to see the possible solutions clearly. For example, sometimes there are serious issues that you feel you need to address, but that you cannot resolve. What do you end up doing? Worrying. There can also be serious issues that you actually can do something about. In those cases, too, if you are not careful, you may also find yourself worrying. Once you are overwhelmed by anxiety and other unhelpful emotions, it will be very difficult to plan or make clearheaded decisions. You will not be able to look beyond the obstacles to notice the opportunities. ~ 17th Karmapa