Even one shoe can be needed. I know a young teenage boy in our village that was born with only one foot. If I ever come across a left shoe, slipper or any footwear, I will stop and pick it up and put it back in circulation. So, even one shoe doesn't have to be lonely!
Oh how serendipitous! And the shoe in the image I found is a leftie <3
Yes, I noticed that too! ;)