The case for having any beverages at your desk in the first place is one of basic human biology. Your mom was right when she told you to drink some water: Mild dehydration isn’t a notable health risk, but the spotty research done on the topic suggests that being thirsty is distracting. Slaking that thirst might help you return to your spreadsheets and get out of the office on time. Even if you’re not thirsty, people tend to report feeling more alert after having some water. Water is the foundation of your beverage kingdom.

And then there’s caffeine. Research has shown that it improves alertness in moderately sleepy people—for instance, those who underestimated the size of their sandwich and are now slowly slipping into a food coma at their desk. Maybe you stayed a little too long at happy hour last night and need a coffee to help ease your headache. Or maybe you’ve just been riding around on the planet with the rest of us for long enough that you need a Diet Coke on a spiritual level. Add it to the lineup.

Completing the desk-bev triumvirate is where the magic happens. A third beverage is your wild card, a chance for a little bit of random pleasure in a period of the day that is otherwise not your own. One of the reasons people go so wild for random snacks in the workplace is that popcorn or cookies allow a moment of disengagement from work that feels autonomous. Since water and coffee are the only drinks many workplaces provide, tracking down a third can be an excuse to leave the office for a moment, even if it’s just to run to the nearby corner store. Small, regular pleasures have real psychological value in any part of life. During the workday, acquiring a mango seltzer or green juice can return some humanity to the cubicle farm.