i have a running theory that doorways cause temporary amnesia - especially when at work, but also in the home. the more doorways you have to pass through between point A and point B the more likely said temporary amnesia has of setting in and causing you to forget what you were going to retrieve. They do not have to have acutal doors attached to them, just be framed as a door sized wall-break that you have to walk through. For example if i'm going from my laundry room (which is accessed from in the garage) i have to pass through as many as 6 door frames to get back to my bedroom or the reloading room (aka the spare bedroom). this is why i often stage my loading the car for a trip to somewhere with gun stuff in stages. From the reloading/gun room to the living room. and from there to the mud room off the garage. and then into my car.
i used to work in a restaurant that had a similar problem - too many doorways between the kitchen and the walk-in coolers and the dry storage pantry... i cant begin to recall how many time id walk into the cooler and find that not only had i forgotten what i'd come in for, but another co-worker was already in there staring mindlessly at the shelves trying to remember what they were looking for too! That was one of my early beginnings of confirming said theory... although its origins pre-dates said workplace by several years