My wife (or husband) told me to get six cans of Sprite from the grocery store.
I had just realized when I got home that I had picked up 7-Up.
Alright listen up, slowpoke! The humor lies in the fact that the person was asked to get Sprite but mistakenly bought 7-Up. They are similar lemon-lime sodas, but not the same. It is a silly mistake, just like you reading this explanation!