Sitting in vipassana retreat. Silent. Very serious. I found it joyless at times. The teachers, while well versed in their field, took themselves pretty seriously too. I didn't see them smile much.
Anyhow, well into the first long sitting, a guy sitting in a yoga posture in the middle of the room started to do a loud, specialized, breathing technique. In that quiet, serious meditation hall, it was LOUD. I loved it. As I listened to him, my sense of humour kicked in. I was caught by the sound of it; it sounded a bit like a cat trying to throw up a hairball.
Spiritual growth has a certain dignity to it. Yet humour does too, when it's not pointing fingers, or hiding from the pain of reality. Real humour is about the absurdity of life. The longer we live the more we come to see that each time we try to settle on a truth or fact or take things too seriously, we find spinach in our teeth. Humour keeps us humble; it's what makes us human and it serves as a good counterpoint to self-importance or too much piety.
When I sat in that meditation hall after the hairball thing stopped, I could feel that the pressure in the hall had released, as though everyone had taken off a tight shirt. Even if it wasn't his intention, and even if it made the leaders frown, it was the perfect way to break all that difficult energy.
Taken at the same time, spiritual growth and humour invite a sense of tenderness in us, an understanding that we are all in this together.