When you walk into the kitchen for something and immediately forget what you walked there for, and have to go back to the physical location where you started out before you can remember what you were going to the kitchen for. Can happen repeatedly.
X: Why are you standing in front of the sink?
Y: It's the damned kitchenheimer's. I'm gonna have to go back out to the living room. It's, like, the third time. (Starts out) Oh yeah--I wanted to get some ice cream.