Wit is one of those traits about which it is extremely hard to be unselfconscious. But whereas having large breasts is the both the medium and the message "your babies would thrive", wit is an endowment that goes completely to waste in a person who thinks their wit is the goods. Its not. It is only the medium. And its yardstick, regardless of self satisfaction or the chuckles of others is just this: did the message escape anyone? Did the point go home like a dagger? Clever words that change no minds are suspect, as if no truth had been told.
Just because you can say it well does not mean you should not watch what you say.