Yeah I also worked grocery for a long time and this is true. They also really hate being told they parked wrong, or they parked their stupid car in front of the shipping area, or they're triple parked.

They hate reading too. It doesn't matter if a giant sign indicates something, they're still going to ask or get mad.

One time we had to rearrange some shelves to make room for a bakery expansion, so that involved changing where stuff was located. There was a ton of confusion at first, but most people acclimated. One very obese elderly woman apparently was unable to find anything so she had to do several laps around the store finding stuff. At the register she was clearly exhausted, but had enough energy to scream at us, getting more belligerent until she made the claim we were attempting to kill our elderly customers (even though 99% of them were elderly). We tried calming her down but she demanded to use the phone to call the cops on us. We refused, but she came back the next day with a cop who interrogated us. America