The first tire shop he went to refused to mount the tires for him because the size on the sidewall was different than the OEM size for the car.
I have heard that one as well. I laughed and asked him what car came with those crazy expensive 22" wheels and rubber band tires that he proudly displays in his showroom and what truck came with those 3 foot tall tires he has for sale.... Crickets.
He wanted to know what car my 275-60-15 drag radials were going on. Absolutely no car ever came with those. So he asked what the OEM size was. I told him F60-15 fiberglass belted polyester bias ply tires. Deer in the headlights. His father probably isn't old enough to have seen anything but radials.