That is intriguing. We all laughed at a joke that noone else thought was funny, but your situation seems more extreme. Care to write more about your experience?
Not sure what it's caused by, but the whole thing is really apparent in social situations (which often include a lot of joking around). I never have been able to "sync up". My humor is scaled way way up, kind of like if you could hear God's laughter as he observes the universe, in the Russian style. It's not relevant to anything anyone cares about.
I hope that makes sense.