According to Osho, he genuinely finds everything funny because life itself is a cosmic joke, yet he never caters to your sense of humor. His jokes are a meditative device: laughter momentarily suspends the mind, creating a gap free of thought. In that gap he can connect and transmit insight directly, slipping truth past habitual defenses.
I laugh at life and use jokes not to please you, but to pause your busy mind so real understanding can slip in.