But a possible soccer career was derailed during a family trip to Colorado for a soccer tournament that included a stop at Colorado Springs, home to the United States Air Force Academy.
"Dad, I might want to go here," he told his father, Jack Knowlan.
So began the journey of Garrett Knowlan, one in which he received an appointment to the Air Force Academy upon his graduation from high school. He was commissioned a second lieutenant four years later. He possessed enough of the right stuff to become a highly regarded engineer and test pilot for the Air Force, reaching the rank of major and routinely receiving top ratings in performance reviews that yielded praise from his superior officers.
In what Knowlan saw as perhaps his most important role, he was a strong Christian who applied his faith in being a devoted husband and father of two young boys.
Tragically, his life was cut short Oct. 11 during an Air Force training exercise in Pensacola, Fla.
"We lost an amazing young man and also a great father," Jack Knowlan said during an interview Friday. "It's a terrible loss and we'll miss him. Thursday would have been his 33rd birthday. But my wife Bonnie and I are focusing on the life Garrett led and how it can be an inspiration to others rather than dwelling on our loss."
Jack Knowlan is aware of Air Force investigations probing the circumstances of his son's death. So far he is satisfied with the progress. As of Friday, though, he still didn't know the exact events.
"I think what happened was an accident," he said. "Somebody made a mistake, but becoming angry and pointing fingers won't bring Garrett back."
Garrett Knowlan lost his life while participating in a four-day Air Force survival-training program. According to an Air Force fact sheet, the course includes instruction in signaling rescue aircraft, hazardous aquatic life, food and water procurement and life-raft procedures. It also involves parasailing in Pensacola Bay to simulate a parachute drop, which called for participants to reach an elevation of about 200 feet and then be lowered into the water.
Knowlan had landed in the water and was afloat in Pensacola Bay when he was struck by what has been confirmed to be a military vessel.
According to Maj. Carla Gleason, an Air Force spokeswoman stationed at Randolph Air Force Base in San Antonio, Knowlan's death was the first since the training program began in 1994.
"It's a tragedy," Gleason said. "We're not just concerned with the investigation. We're also mindful that this is a terrible loss to Major Knowlan's family and friends. It's also a terrible loss for our country."
She added that safety- and ground-accident-investigation boards were convened upon Knowlan's death and are probing what happened the day he died. A full report, once approved and presented to Knowlan's family, will be released to the public.
"The Air Force is doing all they can," Jack Knowlan said. "They've been a huge help to Garrett's wife Megan and his two boys. So have Garrett's classmates from the academy and his peers where he had been stationed."
Knowlan's sons are Beckett Jack, who will turn 3 years old in December, and Levi Asher, 14 months.
"Garrett would want us to take care of Megan and his two boys, and we're going to do it," Jack Knowlan said.
Perhaps the reason Jack Knowlan knows his son would want it that way is because his son would have done the same thing for somebody else.
"Garrett was the type who would try to help someone he saw was in trouble," he explained. "Even while growing up, he treated everybody equally. He was competitive but also compassionate. He was well-liked because of that."
According to his father, Garrett Knowlan's heart belonged to engineering, not flying.
"He never got a pilot's license at a young age, Jack Knowlan said. "He wanted to be designing and improving planes, not flying them. But that changed over time."
Something else that changed over time -- Garret Knowlan's faith.
"Growing up, Garrett's faith wasn't particularly strong," Jack Knowlan said. "But there was a transition after he first left for the Air Force Academy. It's safe to say the academy has its ways of breaking someone down, and I believe he turned to his faith during that time. He became a bolder and stronger witness for God. The whole package came together."
It was a faith that withstood the test of time, through Knowlan's study at the academy, his first assignments as an officer and juggling military life with family life.
The day after his son's death, Jack Knowlan arrived in Florida to help begin the somber task of settling his son's affairs. While there, daughter-in-law Megan presented him with his son's Bible that contained underlined passages. One was from Philippians 1: "For me to live is Christ, and to die is gain."
Jack Knowlan believes that reflects his son's faith perfectly.
"My wife and I are comforted in knowing where he is," he said. "I'm convinced that something will result from this loss that will overshadow Garrett's death. We're getting 30 to 40 cards from people we don't even know every day. And I want to stress that the support we have received from the community and Southeast Missouri has been amazing."
The Knowlans also are grateful for the support of the Knowlan Family Memorial Fund, established to provide assistance to Megan, Beckett and Levi.
Donations should be made payable to the Knowlan Family Memorial Fund, P.O. Box 363, Jackson, MO 63755.