Boundaries get talked about like they're a wall — something you build to keep people out. That framing makes them feel harsh, and it's part of why so many people avoid setting them even when they badly need to. A more useful way to think about a boundary: it's not a wall, it's a fence with a gate you control. It doesn't shut people out. It just means you decide when the gate opens, instead of it being open by default to whoever pushes.
The hardest boundaries to set aren't with strangers — they're with people you actually like, at work or at home, where saying no risks a relationship you value. That's exactly why so many boundary conversations get skipped or softened into vagueness ("I'll try," "maybe next time," "let me see") instead of a clear answer. Vague non-answers feel safer in the moment, but they train the other person to keep asking, because they've learned that pressure eventually works.
A boundary that actually holds tends to have three things: it's specific, it's stated before you're already resentful, and it doesn't come with a defense attached. "I don't take work calls after 7pm" is a boundary. "I don't take work calls after 7pm because I'm really trying to protect my evenings for myself and I hope that's okay" is a boundary wrapped in an apology, and apologetic boundaries get negotiated a lot more easily than plain ones.
The discomfort of setting a boundary is real, but it's front-loaded — it's worst in the moment you say it, and it fades. The discomfort of not setting one is the opposite: small and tolerable at first, then compounding, until the resentment is bigger than the original ask ever was. Most people are optimizing for the wrong kind of short-term comfort.
You don't need a script for every situation. You need one clear sentence, said early, without the apology tax attached. That's most of the skill.