The most common dopey talk is in grocery stores by customers that joke around about prices of items, discounts, etc. As in, an item doesn't scan so it automatically becomes free.
*You enter the room with taco bell only to be eaten by yourself*
Asshole: "HEY! YOU BROUGHT ME LUNCH! HAW HAW!"
Clerk: "Is there anything else I can get you?"
Customer: "Yeah, how about the winning lottery numbers!?"