Across various industries and worlds, there's a goal that's easily translatable: to excel. Great achievement—won through dedicated work and a determination to improve—has been associated with Rolex for generations, making the brand's collaboration with ambassadors from a range of fields feel right. In an ongoing partnership with Rolex, we explore the journeys of these exceptional women.While there's something absolutely inconceivable about what it must be like to be 19-year-old golfer Lydia Ko—ranked the best in the world at something at an age when most of your contemporaries are pacing dorm-room halls—there is plenty to relate to. Consider her determination to have fun while working and enjoy the journey. Or her focus on balancing time with friends and a big career. As one of the youngest athletes we are profiling in our partnership with Rolex, plan on hearing Ko's name for a long time…though maybe don't bank on her name sitting on leader boards for decades to come: She's famously said she'll retire at thirty. "I want to retire when I'm still playing well, not because I can't compete anymore, and 30 is better than 29," she explained while sitting in a sunny studio. "This is my fourth year on tour, playing 15 years. That's enough."On her early start:"We visited my aunt in Australia for a holiday—at that time I was living in Korea—and in her free time she'd play golf. When I was five I obviously had no idea what golf was, I followed her out and she said, 'Hey, why don't you have a hit with my club?' I hit the ball, so she thought that was pretty cool and went to the golf shop and got a couple of her clubs cut down to fit more of a five-year-old size."Because I started then, I felt like I missed out on my teens. I felt like I wasn't like the other girls. I couldn't go out on Fridays with my friends and go have sleepovers. Even though I might have missed out, I'm fortunate to be able to travel all around the world and experience different cultures. I'm a big foodie, so getting to taste different food from places around the world . There's a lot of things I'm very fortunate to do at my age can't do. I've come to learn more that the life I'm living is pretty awesome."On growing up in her sport:"You learn to mature quicker. not going to come to my age and talk to me in a 19-year-old perspective; they're going to be them. Being on tour has helped me talk and think in a perspective that's not how a 19-year-old would, but how a 25-year-old would. It's grown me not only as a player, but as a person. Golf is not only a huge aspect of my career and what I do as a job, but it's a huge aspect in me growing as a person."On age being just a number:"In golf, we all say age is just a number. I started on tour when I was 16, and was the youngest one out there for my first two years. It was always, 'Hey, you're the youngest one!' There are girls who played on the tour for 20 years and I'm turning 20 this year." I remember being with grownups. I first started getting lessons in an apartment , on the basement floor where they had those indoor ranges where you hit to a little screen area. It was more people coming in after work and having a hit—I was always around people much older than me."On how you process being ranked #1:"You don't really think about it that often. When we're out there playing, we're all golfers trying to play the best we can; just because I am the number one-ranked player doesn't mean I'm going to win every week. It's more about consistently trying to put myself in contention. I'm trying to make as many birdies as I can and play the best I can. They say prodigies come and go quickly, but I'm trying to feel fortunate has happened so far rather than think about what could possibly happen in the future."On joining the Rolex family:"Everybody has an image of Rolex as so classy and traditional, and to know that I'm a part of that is amazing. I wear my Rolex with pride. It's been cool to be alongside some of the golfing greats and other sporting legends. At the Masters, I got to have lunch with people like Jack Nicklaus and Tom Watson and Annika Sorenstam. When would I ever have a chance to eat alongside them? It's given me so many opportunities."On the importance of finding balance:"It's so important to balance golf with my life outside of it. That's why I love hanging out with my friends, watching TV, and going to the movies. You can't really think about what's going to happen. There have been so many positives and amazing things so far, I'm going to try and embrace the moment right now."It's really hard in the season to say, 'I want to go out and do something.' Our off-season is pretty much from the end of November to the end of January, so the whole of December I take time off. I don't touch my golf clubs at all. I've done that the past three seasons, and when I come back I'm rustier than when I left, but my body can physically recover. Mentally, I'm switching off and I think that's important. I do some workouts, but not a lot. I normally do a little trip with my friends—go out and do our own barbecue. That's when I'm living life as the person Lydia Ko, rather than the golfer Lydia Ko."On the impossibility of having too much fun:"People say I have too much fun. Golf is known to be quite serious—when you see on TV, very focused and sometimes that comes across as being serious. I'm always trying to have a good time. It's a big goal of mine to keep having fun and be positive. I think that's so important because we're trying to play this game for not only now. I stay focused on the shot when I'm about to hit it, but outside of that I'm trying to enjoy it the most I can. I have a pretty big laugh too so when I laugh, everyone hears and they're like, 'Aren't you having too much fun?!' On being a role model:"It's awesome to hear from a fan, 'Oh, hey, you're the greatest putter in the world,' but to me the greatest thing to hear is, 'You're my role model.' We're not only trying to play the best we can, but to make a difference on our tour and for the women's game. There have been so many great role models who have made the tour what it is today. If I can make a difference, make one more junior take up the game or love it, it's kind of a pat on the back for us."Follow Marie Claire on Facebook for the latest celeb news, beauty tips, fascinating reads, livestream video, and more.