One recent morning at Uganda's Entebbe International Airport, his instructor asked him to explain how the engines worked on a Bombardier CRJ900 plane parked on the tarmac.
His voice struggling to rise above the roar of a plane's running engines, Shema rattled off the answer: "The inlet tubes suck in the air and inject it into the compressor, the compressor squeezes it with the fans, after squeezing it with the fans, it becomes hot," Shema said, playfully gesturing and proceeding to detail how an engine creates thrust.
Shema's curiosity for flight was piqued by a freak incident.
When he was 3-years-old, a police helicopter flew so low to the ground that it blew off the roof of his grandmother's house on the outskirts of the Ugandan capital Kampala while he was playing outside.
"It triggered something in his mind," said his mother, travel agent Shamim Mwanaisha, 29. Her son began peppering her with endless questions about how planes work, she said.
Last year, she contacted a local aviation academy and Shema began lessons at home on aircraft parts and aviation vocabulary. After five months of coursework, Mwanaisha paid for practical flying lessons for her son.
"I felt like a bird flying up," Shema said of his first flight. He had never flown on a plane before.
He flew three times as co-pilot between January and March before the pandemic stopped his practice.
He has since been focusing on aviation theory, and immersing himself in videos about aviation and space exploration on his virtual reality viewer.