(CNN) Just 15 months ago, Collin Morikawa was an amateur, college golf player. In fact, he remembers watching the final round of Brooks Koepka's PGA Championship victory in 2019 with some friends and his team.
But now, aged just 23, he is a major winner himself, having brilliantly won the PGA Championship at TPC Harding Park in San Francisco Sunday, finishing on 13-under and two shots ahead of Dustin Johnson and Paul Casey.
While his victory in just his second major may have come as a surprise to many, it didn't to Morikawa, who said that he "felt very comfortable from day one."
"I'm never satisfied to its fullest," Morikawa told CNN Sport's Don Riddell. "And who knows when I will be, but I just want more.
"I got a little taste of what it's like to win a major championship, to what those other players have won before, and I definitely want it again."
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Morikawa became the third-youngest PGA Championship winner since World War II, behind only Rory McIlroy and Jack Nicklaus. But while people have drawn comparisons between him and Tiger Woods -- who also won the competition aged 23 -- Morikawa believes Woods is on a "completely different level."
"It means that I'm doing something right. Whatever I've been doing, whatever I've been practising, gearing up for, it's all been on the right path to hopefully one day be in the conversation of maybe some of the game's greats," he explained.
"I learn every single day. I'm going to learn a lot from this win, obviously, but I really have to sit down and figure out what I can do a little better because there's always something that someone else is trying to beat you at or trying to copy you, or really get better and beat you every single day."
Although the Californian course was eerily quiet as Morikawa sunk the winning putt on the 16th hole, the rising star -- who describes himself as a "competitor" -- credits his success in part to having his girlfriend, Kat, at one of his tournaments for the first time since lockdown.
And, he says, having a strong family set up has been the platform his success has been built on.
"I think I was just very fortunate to have amazing parents, an amazing family, an amazing support system," he said. "My girlfriend, Kat, and I have been dating for over three years now.
"I've really built a team and it's all about building a team. Everyone just pays attention to the leaderboard; you only see one name at the top. But there's so much that goes into building this team."
And he celebrated with his family following his victory on Sunday, calling his parents who were "screaming" when they answered the phone.
"My girlfriend and I, we Facetimed them after the round when I was waiting for everyone to finish up and they were flipping out, they were moving the camera, covering up the camera, just absolutely enthusiastic for the win.
"It was crazy because on Friday -- my mom never told me this -- but they had a balloon fly up from someone else's yard into their trees in our house, and it was just a number one (balloon). It was a one balloon just floating in the trees, and it never popped, it stayed there. So, you know that's pretty special. I think that balloon meant something, and they might have known that from the start of the week."
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Morikawa was born and raised in the US, but is also of Chinese and Japanese heritage. However, he admits that his ties to Asia "are not as strong as many people would think or believe," with his family either living in California or Hawaii.
He hopes his victory at the first major of 2020 has helped increase his reputation in Asia.
"But every time I've been able to go back to Japan -- I've never been to China, we went to Korea -- it felt nice," he outlined.
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"It felt like I was going back to this is where a lot of my history had started. So it's always cool going back to the roots. It has that extra sense of feeling and emotion that you might not get anywhere else in the world other than your nationality or ethnicity.
"So it's very cool but have I been able to really go out there and put my name out? I don't think so. Who knows what my name is spreading like out there, but hopefully I'm getting bigger out there because the next time I'm back, hopefully it'll be a very, very exciting week or so."