Says he enjoys golf because "the mental toughness needed to play this sport at a high level is unbelievable, and it requires your attention all the time. Although it may not necessarily require the most physical ability, it is by far the hardest sport I have ever played."

Grew up playing El Prado Golf Courses in Chino, California, a 36-hole facility open to the public.

Graduated from Diamond Bar (California) High School in Diamond Bar in 2015. Notable alums from the school include four-time MLB All-Star Jim Edmonds (Class of 1988) and retired women's soccer player Alex Morgan (Class of 2007), who won an Olympic gold medal in 2012, as well as the 2015 and 2019 FIFA Women's World Cups as a member of the United States Women's National Team.

Is a big fan of the Ranger's Apprentice series of books. Likes to watch American Ninja Warrior, and listens to RL Grime and Flume.

Enjoys playing chess and learned to play as a child but gave up the game for about a decade. Began playing again in January 2019 as a senior at Pepperdine, when he broke his wrist and couldn't play golf for six months, so his teammate Derek Hitchner encouraged him to start competing against him in chess. Theegala recalled, "I thought I'd beat him easily. But he destroyed me, so he kind of got me back into chess."

Won a college tournament for the first time, forging a five-shot lead at the 2017 Southwestern Invitational with 18 holes to play and overcoming a final-round 74 to defeat SMU’s Alex Higgs by a stroke in Westlake Village, California.

At Lakeside GC, won the Southern California Golf Association Amateur in July 2019 in dominating fashion. Rounds of 68-67-65-65 resulted in an eight-shot rout of Trip Morris. Won the prestigious Sahalee Players Championship in 2017, finishing regulation tied with Australia’s Min Woo Lee and then defeating Lee in a sudden-death playoff.

Captured his third collegiate title, winning 2019 Alister MacKenzie Invitational in Fairfax, California. Defeated Harrison Kinglsey and Sean Yu by a shot in early-October.

Won his fourth and final college tournament, the Southwestern Invitational, in January 2020, backing up his 2017 title at the same event. Edged USC’s Leon D’Souza by a shot by shooting a final-round 66 to break free from a tie with D’Souza when the day began. Two weeks earlier, traveled to Victoria, Australia, for the Australian Master of the Amateurs, opened 66-68-69 to take a six-shot advantage into the final round. Despite shooting a 75 during difficult scoring conditions at Victoria GC still coasted to a four-stroke triumph over South Korea’s Jang Hyun Lee. Was one of only three Americans in the field.

Reached as high as No. 3 in the World Amateur Golf Ranking. Won the 2020 Haskins Award, the Jack Nicklaus Award and the Ben Hogan Award representative of college golf’s top player. Became only the fifth player since the creation of all three awards to sweep collegiate golf’s Player of the Year honors.

Represented the U.S. at the 2018 Palmer Cup in Évian-les-Bains, France. At Evian Resort GC, in the U.S. victory, went 1-3-0 in his four matches, his win coming in four-ball with Justin Suh his partner.

Made his PGA TOUR debut, at the 2017 Genesis Open. Finished T49 at Riviera CC.