The secret of the joke is that it brings you to a point where you are expecting, expecting, expecting that this is going to happen; then it never happens. And what happens is so sudden… and because you were expecting something you were coming to a tension, and then suddenly something else happens, and the tension has come to such a climax that it explodes. You are all laughter. It is a tremendous release, it is great meditation. If you can laugh totally, it will give you a moment of no-time, no-mind. Mind lives logically with expectations, laughter is something that comes from the beyond. Mind is always guessing what is going to happen, groping. And something happens which is absolutely contrary to its expectations: it simply stops for a moment.
And that is the moment when the mind stops, when laughter comes from your belly, a belly laugh. Your whole body goes into a spasm, it is orgasmic.
A good laugh is tremendously meditative.