I just want to make this quick. If you say "Have a good one" or are a frequent user of "Have a good one" you need to stop. When you say, "Have a good one" what your really saying is, "I'm no good at conversation but something tells me I should say one final thing." Some of you may not have heard "Have a good one" but I doubt it. Here is how it works.
Man 1 - "Ok, see you later Man 2"
Man 2 _ (waves) "Have a good one"
See, man 1 has now been forced back into the conversation. Now he is obligated (so he thinks ) to share the gesture of the "good one" whatever that may be.
Man 1 - "You too"
I suppose there really is no way out for Man 1. Its like playing the "I 8 the skunk" game. Man 1 will almost always have to re enter the conversation if a blessing is used. Something like, "Have a good day", "I hope your day goes well" or "I hope you don't get hit by a truck" demands a return blessing.
To get back to my main point, "Have a good one" is overused and annoying. It is a verbal scourge. And don't say, "Having fun yet?" either.
Next time on Plan 4, We'll see how saying "Hot enough for ya" or the "cold enough" variant can get you killed.