If a grocery store trip doesn’t always feel like a peaceful getaway for you, you’re not alone. Different stores have their own guidelines and customs that shoppers have to get used to, and rules of etiquette are hotly debated.

At Aldi, for example, some shoppers feel they encounter a string of stressful experiences, from identifying the generic versions of items on their lists to keeping up with the person at the register. They’ve taken to the term “Aldi anxiety” to describe what it’s like to shop at the budget retailer.

But no topic seems to make grocery customers as heated as carts. Shoppers are losing it over other store-goers leaving their carts in the middle of the aisle while they grab items from the shelves. For other shoppers, letting your 5-year-old push the cart is one of the rudest things you can do at the grocery store.

Shopping carts are also being compared to the state of humanity. A popular theory on social media claims that returning a shopping cart to the parking lot corral is the true test of good moral character — doing small, virtuous things when nobody’s watching. However, some people are warning that the “shopping cart theory” might be counterproductive and actually create more discriminatory judgment among shoppers.

The shopping cart theory on social media ties the act of returning your cart to humanity’s innate ability to maintain and respect social order. Philosophers as far back as Aristotle have claimed that good citizenship and ethical living involve caring for shared property, an idea that’s reflected in discussions of grocery store no-nos you might not know you’re doing.

“No one will punish you for not returning the shopping cart … you gain nothing by returning the shopping cart. You must return the shopping cart out of the goodness of your own heart.”

By Jared Kaufman