...that whenever I go shopping, everything I want is either on the top shelf, too high for me to reach, or on the bottom shelf, too low for me to bend down?
First you need to locate the product in the shop, then you go to try and find an employee, by which time you cannot remember what it is you wanted to buy.
Same in Libraries. I always have to get on the floor to get the book I want. I am sure the number of times I have to grovel like this must be completely disproportionate