This is a shorthand for the overused expression, "Have a good one," (derived from the even more overused expression "Have a good day") and is slowly catching on to be much more hip!
As I drop my friend off and he leaves the car, I shout "Have one!"
to have your charm or charisma working at full capacity; ain't no stoppin' ya now, especially with reference to scoring with a chick. You can't say or do anything wrong; your charismatic appeal is at peak level.
Talking to the foxytrollop at the end of the bar and trying to get to home plate was like placing a stick of butter in a microwave! She melted, and was up my ass like a proctologist on Monday morning!!! I guess I had my mojo rising that night!
when someone asks you a question or sends you a bullitin on myspace about what is your favorite color, song, food, species of bird... etc... and you don't have one.
While our lifespan is the number of years we will live, our healthspan is the number of healthy years we will have and our sexspan is is the number of years we will continue to be healthy enough to continue having an active sex life.
A lighthearted reaction upon receiving disappointing news of some sort. Usually something that isn't a particularly a big deal, esp. when it primarily affects someone else - sort of a mild schadenfreude. Sometimes doubled or tripled, and possibly said in a sing-songy voice for added comedic effect to imitate a muted trumpet, which is how the meme originated.
You didn't get any napkins with your takeout pork fried rice? Womp womp.