I’ve been sitting with that duality a lot lately. Because for every yes I’ve ever said — every obligation I leaned into, every expectation I absorbed — there was a cost. And for every no, there was something protected.

The “doing” may be what people celebrate, but the “not doing” is what made everything possible.

The moment that opened my eyes

In 2021, I withdrew from the French Open. People around the world had a lot of opinions. 

That moment stands out for me because it opened my eyes to something I hadn’t fully let myself see: you don’t always have to do things that people expect from you. You just have to protect yourself, and know yourself well enough to understand your own boundaries. I’d been a kid playing on public courts where nobody knew who I was, and then all of a sudden that shifted. In the beginning, I wanted to do well for everybody, which caused a lot of stress. The French Open was the moment I finally let that go and figured out I had to do it for myself.

The honest truth about ‘no’

I want to be clear: saying no is not easy for me. But over time it has become a more familiar discomfort.

For a long time, I didn’t like inconveniencing people. I tried to make life easier for others, which meant saying yes to things my heart wasn’t in or I didn’t have the energy to really show up for. What I’ve come to learn is that showing up halfway carries its own cost. Saying yes when you mean no doesn’t actually serve anyone, least of all yourself.

I used to be afraid that saying no meant disappointing people. And believe me, that fear is still there sometimes. But becoming a mother shifted something in me. Now when I say no, it isn’t just about protecting myself, it’s about protecting my daughter too. That realization makes the discomfort easier to sit with, even if it never fully goes away.

There’s this idea that “doing it all” is something women should aspire to, and I don’t think that should be glorified. You can’t be everything to everyone without losing something of yourself. Sometimes it’s actually kinder to say no.

I’ve also learned that asking for help is not the same as being a burden. When I was younger, I’d carry everything myself and call it discipline. Over time, I realized that having a supportive community means surrounding yourself with people who actually want to show up for you. I’m not inconveniencing them when I ask for help.

In a way, that is its own kind of no. No to the story that I have to do everything alone.

What it looks like to protect yourself

In practice, protecting myself is made up of small, daily decisions.

As a professional athlete, I’m very in tune with my body. I’ve learned the difference between a good kind of tired and a deeper fatigue that means something is off. When I feel that fatigue, I don’t push through it anymore. I respect it.

I’ve also had to learn how to rest in a different way. I grew up feeling like I wasn’t good at anything other than tennis, and I carried that with me for a long time. I thought if I just worked hard enough and achieved more, I’d eventually feel settled. But arriving at this place in my life doesn’t automatically teach you how to slow down.

Now, exhaling looks different. It’s coming home and being with my daughter, being fully present during bath time, reading her a story before bed. Those are the moments I choose over everything else, the moments that actually recharge me. There are moments where I choose to step away from something work-related earlier than I might have before, because being with my daughter matters more.

The boundary I’m most proud of is also the simplest. No one outside of my personal inner circle has seen my daughter. When I first set out to pursue professional tennis, I never expected the level of attention that would come with it. Being a public figure has made me even more intentional about what I keep private. In an age of constant access, that choice and protection is very important to me.

What I want you to know

If you are a young woman — or anyone still figuring out what you’re allowed to want — I think it’s important to know that you can have both ambition and limits at the same time. You can go after something fully and still have a say in what it costs you.

I used to think success meant saying yes to everything that came with it. Now I see it differently. I’ve been able to achieve what I have by holding boundaries. Because when I protect my peace, I can perform from it, parent from it and prioritize my mental health. At the end of the day, you’re the only one who has to sit with yourself: your feelings, your decisions, your dreams and your challenges. That’s what makes these decisions matter.

People ask what I did to get here. But the truest answer might be this: I got here partly by deciding what I didn’t have to do anymore.  

The opinions expressed in Fortune.com commentary pieces are solely the views of their authors and do not necessarily reflect the opinions and beliefs of Fortune.