“This is my boundary, and you’re not crossing it either,” Astrid shouted at Harmjan in Season 1 of B&B Vol Liefde. Harmjan had used more spices than Astrid had specified. Looking back, she said, “I guess I felt safe enough to let myself go.” Harmjan was unable to set his own boundary in response.

Setting boundaries is rarely just a matter of assertiveness. It often involves loyalty, safety, and the place you occupy within a system. It touches on aspects that are already complicated to determine for yourself, let alone for someone else. The word “boundary” is used indiscriminately. Not conforming to someone’s self-imposed recipe can hardly be called a boundary. Yet it is crucial. Boundaries help you stay true to yourself, preserve your energy, and maintain healthy relationships, both at work and in your personal life. Saying “no” is sometimes the form it takes, but a boundary starts with knowing what is yours and what is not. It touches on the fear of being walked all over, the tendency to please others, and the courage to stand up for yourself. And often, it also touches on what you were taught at home about loyalty.

Before you can set a boundary, you first have to ask yourself: what is acceptable to me? How far am I willing to go? And how do I communicate that without things escalating? I’ve seen this happen a lot in the legal profession. A boss with yet another case. A “no”—or a slightly more polite version: “not right now, but I can do it then and then”—is unacceptable. Just handle it. Young, ambitious people who thought that was just part of the job and even slept under their desks at night to keep up. The result? Burnout and, ultimately, a breakdown. Knowing your limits is one thing; communicating them is a learning process. Your body often sends signals: stress, insomnia, irritation, or tension can be signs that a boundary is being crossed.

To be honest: setting a boundary once cost me my job. My contract wasn’t renewed after I tried to rein in a ranting boss during an editorial meeting—also on behalf of colleagues who didn’t dare to do so. I don’t regret it. It brought me to where I am today. In coaching, it’s rarely just about learning to say “no.” It’s about exploring where you let yourself down, why that made sense at the time, and what it takes to stand firmer without losing the relationship.