Wow I've been looking for this thread my entire life. Or like, since I got my job anyway.
One of the rudest people that sticks out is a woman who came up to the counter and brashly demanded, "How sweet is the apple juice?" which how am I supposed to know the exact sweetness of any single bottle of apple juice? So I just said, "I think it's just your standard apple juice so it shouldn't be overly sweet". She was just fiddling about in the fridge and then she says, "I had one that was a light colour earlier, do you have any more that colour?" If you had one earlier, why are you ******* asking me how sweet it is, you should know! So I just told her again, "They're all from the same batch so they should all taste exactly the same." Then she goes, "It's not the taste I care about, it's the sweetness". Sweetness is part of taste, you awkward old pork. In the end she banged it on the counter and was just like, "FINE, I'll TRY it". I remember her husband was lovely though, poor guy.