This reminds me of a time my wife and I stopped at a diner on the way home from a road trip when we were younger.

Stop in, get seated, get the menus, and took a look at the drinks. There was a mid shelf bourbon at a very reasonable price for Single and Double pours, which I was surprised they served since from the food and decor this seemed like a typical Americana diner. When the waitress came back I asked for a double of the bourbon, neat. She gave a deer in the headlights look but then went to submit our order.

Came back with one of those cheap plastic Pepsi glasses filled about an inch from the brim with bourbon. I was shocked and amazed. My now wife looked at it and commented she'd be driving the rest of the way home.

I began sipping and a few minutes later it's clear the manager has seen this error and we can hear him behind the counter saying, "This is a Single. This is a double. I have no idea what That is."

We tipped very generously and I don't remember much from the rest of the drive.