What Is It With All The Thank Yous?

[At the front counter of a diner, paying in cash.]

Cashier: “Thank you.”
Me: “No, thank YOU.”
Cashier: “Seriously, thank you.”
Me: “Just so you know, I’ll be the last person to say thank you.”
Cashier: “Okay, thank you for telling me.”
Me: “No, I’d rather thank YOU.”

[She hands over my change.]

Me: “Thank you. Seriously. No need to say anything e-“
Cashier: “Thank you.”
Me: “Ha. THANK YOU.”

[I race for the door, open it, and-]

Cashier: “Thaaaaaank you!!!”

[I exit, wait for the door to almost close, then shout through the crack-]

Me: “Thank you!”

[Minutes later, I’m unlocking my car in the parking lot… The Cashier sticks her head out the back door…]

Cashier: “Thank YOU!”

[I leave well enough alone.]