Support that I am not a retard: (email response from a buddy of mine who was a tech at a Jeep dealer in Seattle for a number of years:
He described exactly what I was trying to do. I am vindicated.Mike, I hate when those chrome caps come off. They are pain. If that happend at the dealer and it was really rounded off, I would take a 12 point 18mm socket (provided the it started out at a 19mm nut) and beat on with a hammer, and then it would usually come off.