No, actually it's frustration.

Older customers with actual knowledge often get that way when they have dealings with congenitally-stupid millennial youths in sales/customer service. Too many num-nut kiddies out there grew up in child-centered, helicopter-parented households, and as a result turned into narcissistic/brittle kidults.

It's why they have such an issue admitting that they're wrong.

It's why they respond "not a problem" when thanked.

Because, to them, the customer IS the problem.