Whoever coined the phrase "Customer is always right" clearly didn't have any idea about the fact that customers can, at times, be a royal pain the butt!
Any person who has ever worked in the retail sector presumably knows the deep-rooted witticism: "The Customer Is Always Right." While this is a benevolent recommendation for good customer service, it doesn't mean it's valid! A few customers, since they are humans like everyone, make blunders, be that as it may, the waiter winds up paying for it.
They may have had an awful day, feel excessively enthusiastic and take it out on the closest individual, who simply happens to be their waiter. A few people are extremely farfetched in their requests and anticipate the unthinkable. What's more, obviously, there will be a couple of customers out there that are simply numbskulls, plain and basic. See for yourself: