Why don't you run up an alley and holler fish?

I was at the grocery store today. Since it's just a small store, there isn't a conveyor belt to put your groceries on, just a small platform about the size of two gallons of milk and a bag of Red Vines (standing on end.) That means that you have to wait until the person in front of you has been rung up before you can drop your groceries on the little ledge.

The man behind me had his arms full; he must be from the same camp as me, the I-only-need-milk-crap-I-also-need-eggs-oh-and-also-mayo-and-I-almost-forgot-bananas-are-those-Ding-Dongs-on-sale-I-don't-want-to-go-back-up-front-and-get-a-basket-dangit-hurryuphurryuphurryup-checker-outer-lady. As soon as my last can of nacho cheese had been cleared, he unloaded his food pile. He did it so quickly that the checker looked up, surprised and asked, "Is this all together, then?"

I, with my extraordinary ability to make all normal situations awkward, turned red and said, "No." Blush, blush, blush. Perhaps sensing my (not really, but seeming) embarrassment, the checker said, "Oh, okay...unless you WANT to pay for his, too."

"Hahaha" went the checker lady.

"Hahaha" went the overburdened man without a concrete grocery list.

"Hahaha...nooooo," said I in a weirdly sing-song, strangled voice that suggested I thought they really would make me pay for his groceries.

Then I stood there, marinating in the awkward silence I'd single-handedly created, wishing I could be more witty on my feet. Only as I walked away did I think of the comeback: "Only if he pays next time."

HAHAHA! ZING!

Okay, still not perfect, but better.

Anyway, it got me thinking about realistic dialogue in stories, and how much it bugs me when people get this witty banter back and forth and back and forth and backandforth, because yo, I never think of the right thing to say in front of people, much less the guy I'm crushing on. (My actual response one time when the cute guy in my class spoke directly to me: "Mehhrgplbbb." Followed by raucous laughter from the whole class.) Why can't we read more of that??

I'm pretty sure a whole book of two people hemming and hawing would get boring fast. And isn't it kind of therapeutic to get some snappy comebacks in when two of your characters are arguing?

There's an old Don Knotts movie called "The Ghost and Mister Chicken" that I love. Don Knotts plays, of course, a bumbling sort of guy and one of the things about him is that he's very tongue-tied when he gets nervous, which is pretty much the whole show. At one point, the mean guy yells, "Who do you think you are?" and he responds with, "Drop dead, that's who!" and then he storms off. I die laughing every time. He is also the mastermind behind, "Why don't you run up an alley and holler fish?"

I love that his character isn't putting the bad guys in their place. He's just a normal guy, trying to be brave but getting it all mixed up anyway. Making normal stuff awkward. My man. *fistbump*

So, the question is, how do you make sure your dialogue sounds realistic, without getting too ho-hum? Do you like it when characters are all quick and witty and snappy all the time?