No they did not.
Most tutorials I looked at connected to ends of the potentiometer to 5v and ground and the middle pin to the lcd.
I have a bachelor's in computer science and a very basic understanding of electronics, I can tell that of course I don't need to connect both the ground and the 5v to the potentiometer. I thought that the level of the 5v line would determine how high or low the contrast should be, so I only put the 5v line.
As it turns out what matters is how much current I allow to flow between the lcd and the ground. I realize now that I can just ground the pin since that contrast works fine for me and forget about it