My first job (not including the paper route) involved lots of cardboard boxes. I worked at a lighting store with a large showroom. We could only store about 25% of the empty boxes for them in the basement. Part of my job was organizing the boxes and when some one would purchase a fixture from the showroom I would have to bring up a box and pack it up. I developed the skill of being able to look at a fixture and hold the volume of it in my head while I went down stairs to find a box that was only slightly larger than the object. Unfortunately I never needed this skill at any of my future jobs.