Well a sense of humor means exactly what it says - it's having a sense when to use humor and when humor is being used. People who are said to have a poor sense of humor are people who don't get most jokes, or maybe get obvious jokes, but miss out on the more subtle ones. Personally, I think sarcasm is God's gift to us humans, haha. Really, I use sarcasm all the time and most people I talk to have a good enough sense of humor to catch on. When I find someone who doesn't get my sarcasm, I also find it difficult to be funny with them, because that's just my personality and sense of humor. You just have to remember, not all people "GET IT," you know? You gotta find your niche - find people who get you and laugh with you. Hey, jokes should be slightly offensive. If someone can't take it, then that's their problem, not yours!