Anyone who has ever worked a customer-facing job can relate to wanting to walk out the door and never come back when they see some kinds of clientele approaching them. There are certain people out there whose personality may as well be summarized as 'pain in the butt to underpaid employees', and most of the time those on the receiving end don't get the pleasure of giving them a piece of their mind.
That being said, this isn't always the case. For somebody like u/BaatNiet, it offers an excuse to get creative with those who are difficult to deal with. Revealing the entertaining way in which he sometimes baffles customers that visit the store he works at, Redditors were also amused with his trickery. We've all got to find ways to make the hours pass on a slow day at work, and confusing rude people seems as good a method as any.