Kim burst onto the scene late last season when he won the final regular-season PGA Tour event to sneak into the FedEx Cup Playoffs at the last possible moment.
The young South Korean had been racking up a significant number of top finishes but as a non-member would not qualify for the post-season. But with his win at the Wyndham Championship late last summer, Kim earned automatic PGA Tour membership to qualify for the playoffs.
He'd advanced to the second post-season tournament, the BMW Championship, and ultimately finish the 2021-22 season ranked 35th.
A month later, he cemented himself as a player-to-watch as he became the breakout star of the Presidents Cup playing for the International Team.
On Wednesday, Kim turned 21, and celebrated his birthday with a fellow tour pro who also happened to be born on the same day, six years earlier.
That tour pro would be World No. 1 Scottie Scheffler, who turned 27 alongside the newly 21-year-old Kim.
Per an Instagram post by Kim from Wednesday, the pair celebrated the day together with birthday sparklers sticking out of cookies.
Underneath Kim's post was a heartfelt caption with Kim calling Scheffler one of his "closest" friends.
And then also pointing out that the major winner likes to give him a hard time.
"21st birthday and sharing it on the same day with one of my closest friends, big bro, advice giver, and most importantly who gives me the hardest time in the world for pretty much almost everything."
Both Scheffler and Kim are in Connecticut this week for the PGA Tour's Travelers Championship.