When you get to where you were intending to go, you forget why you were going there in the first place. Not to be confused with being stoned, destinesia often occurs during working hours, and is the cause of much frustration.
John ran down the stairs to the dry storage and walk-in, but when he got there he couldn't remember what he needed. Consequently, he had to run back upstairs to the kitchen, and look at his prep list again. Damn you, destinesia!