“I once burst into tears when a waitress asked me if I wanted coffee or tea, because I was so hungover I couldn’t decide.” 

So confessed my best friend—the same woman who, at 16, waited breakfast tables at a little restaurant in central Massachusetts where septuagenarian ladies would routinely tip a quarter. 

What is it about brunch? The same people who show up for dinner reservations 10 minutes early, are gracious with servers, and send thank-you notes to Aunt Edna for that nice scarf are the very ones who roll into the Cracked Cup Diner in our pajamas. We’ve got eyeliner smeared to our hairlines. We’re weeping into our bloody marys about poorly framed Instagrams.

I conducted an informal survey of onetime waiters that reveals brunch as the number-one most-loathed shift. And having witnessed loved ones (and, ahem, ourselves) at their very worst during the first meal of the day—stealing seats to save for late friends; lingering over pancakes for three hours while others wait for tables; letting kids run amok and sticky-fingered—we want to figure this out. Why does human nature bottom out over a plate of eggs Benedict? I asked a seven-year brunch-serving veteran and an etiquette expert to weigh in.

Abigail Taylor of Somerville, Massachusetts, has seen things get really real at brunch. “If you end up being the new person on the block, you have to work brunch. It’s kind of a hazing thing.”

The issue, she thinks, is that it’s the first meal of the day: “Everybody’s hangry. They’re usually hungover. They probably had to wait around for their friends to get their shit together so that they can get to the place. Then they usually have to wait in line. There are all these roadblocks to getting to the food.”

And they’re thirsty. Really, really thirsty. “Everyone’s pissed, and they want, like, 17 beverages,” she says. “Coffee, cream, milk, Stevia, and then also a bloody mary. They want all these garnishes. They want water. They want juice.” Then there’s brunch food: “That comes with all these sides, too: maple syrup, butter, toast, jam, hot sauce. It’s not like a dinner where you put one plate down on the table.” Combine that with relatively low menu prices and small tips, and you can see why brunch is a waiter’s nightmare.

It’s something to keep in mind before you roll into your favorite restaurant ten deep and ravenous, suggests Lizzie Post, etiquette expert at the Emily Post Institute. Check yourself and your hangover: “Can you function? Then you’re probably OK. Can you not function? You’re probably not OK.” She takes issue with those who stroll in in their bedclothes, too: “Living in a college town, that’s something you see now and again. I’m like, ‘Dress yourself!’”

Secondly, Post says, consider that the restaurant might not be able to accommodate your group coming in piecemeal. The place makes money every time the table turns, so you’re unlikely to get a four-hour rolling reservation for your shifting party of six. But if you’re going to do that, and management is copacetic, request separate checks as you sit, says Post. Because everyone might plunk down a $20 after the last mimosa has been drained, but as she notes dryly, “Nobody gets away from brunch under $20.” (Some servers argue that separate checks are time-consuming to handle, so if you can avoid them without stiffing your waiter, do.)

When it comes to tipping, Taylor adds, if you’re in a large group, “Remind yourself how math works, because if you split a tab between cash and credit cards you have to remember to tip on cash, and not just credit.” She routinely sees servers “get screwed over” by hangover math.

But why must you, an average diner looking to have some damn eggs and coffee, be so self-aware when—my God, those lights are so bright!

Consider one of Taylor’s worst brunch horror stories. “There’s a burlesque take on The Nutcracker during the holidays called the Slutcracker. There was a matinee showing. We got completely slammed.” Right after the dolled-up Slutcracker fans sat down to order, she remembers, a 5K run called the Jingle Bell Run wrapped up—and 100 of its stinky, sweaty runners came right in to drink beer at the bar. “It was packed,” she remembers. “And they stunk up the entire place.”

The Slutcrackers began to wail: “It stinks! We gotta get outta here!” They began to leave in droves, the pancakes and eggs they’d ordered piling up in the kitchen window. “We probably wasted thousands of dollars on food,” says Taylor. “There was no way to stop it. It was this machine of horror.” There were only four servers working brunch that day; few made more than a handful of tips.

Today, Taylor “can’t go to brunch without feeling stressed out for everyone who’s working around me because I have PTSD from dealing with brunch. I have to put on, like, horse blinders, and hold the menu around the perimeter of my face.”

Brunch might be the one meal where kindness overkill is the way to go.

Pro tip to avoid becoming awful at brunch: Have a handful of granola or a piece of toast before leaving your house. Don’t get to the restaurant hangry. “If you’re really hungry and you’ve slept through breakfast and it’s starting to be lunch time,” says Post, “that can always affect our mood.”

And try to order all at once, begs Taylor, given all those sides and drinks. Want to camp out at the bar for a while with a big revolving group (which is often a better option than taking up a table)? Call ahead. Any more than 10 people, she says, and you’re going to want to give the restaurant a heads-up so they can prepare.

Got kids who threw Cheerios everywhere? Make a stab at cleaning it up. A 30 percent tip isn’t going to compensate for a huge mess, says Post. Although a generous gratuity is great, “don’t just throw money at a problem. I think it’s disrespectful.” But if you’re being shooed out the door by management, go! “In an effort to get you out the door, they might say, ‘Don’t worry about it, we’ll take care everything,’ in which case, listen to them.”

No matter how polite you are, someone else somewhere is shouting down a waiter about overcooked eggs. Brunch might be the one meal where kindness overkill is the way to go.