First, it important is to accept the fact that you are a serious person and make peace with it. This is because what you resist, persists. Change occurs when on

First, it important is to accept the fact that you are a serious person and make peace with it. This is because what you resist, persists. Change occurs when one becomes what he is, not when he tries to become what he is not (See: The Paradoxical Theory of Change — https://www.gestalt.org/arnie.htm https://www.gestalt.org/arnie.htm). Second, it would be helpful to understand where seriousness comes from. Taking everything seriously is an attempt to ward off the fear of the loss of control, the fear of anything that could lead to failure or rejection and the accompanying feelings. Seriousness is the opposite of spontaneity and play. By working on this, you can make a step toward developing a sense of humour. Hope it helps.