One for your head. Three to help cushion the drone landing sites as they deliver our goods in the future.
Take a pillow for yourself, maybe an extra pillow if you feel greedy, and put the rest near your back door where you can reach them with ease. Then you'll be ready, you see, for when the drones sweep across the horizon carrying your gifts, orders, and whatever food you've purchased for the evening meal. That'll hold you for the half-decade or so until some hipsters start hand-delivering glass-bottles of milk to all the rich neighborhoods. Mark our words.