Simpson was convinced by his mother to join the Fitzroy Junior Rugby League club while a young student at the
Rockhampton primary school 'The Hall'. He decided to attend
St. Brendan's College in
Yeppoon for its rugby league program. It was there that Simpson developed greater self-discipline, with
coach Terry Hansen observing "''I knew he'd turned the corner''" after an on-field incident in 2001 where Simpson refused to respond to an opposing player's punches after the ball was played. In late 2001, he was selected in the school's 1st XIII at age 15. In June 2002, Simpson represented St Brendan's College at Confraternity Carnival for the 2nd XIII. In August the same year, he was part of the only 2nd XIII to win the local Open Schoolboys competition against Nth Rocky High School after the 1st XIII withdrew to compete in the arrive alive competition. This historic win came after an overtime game which saw him play a high-impact game. However, in August 2002 he was diagnosed with
cancer. Simpson played what could potentially have been his last game, a pre-season match against
Kirwan State High School, prior to his team being informed of the diagnosis. From 2002 to 2003, Simpson was undergoing chemotherapy for life-threatening
Hodgkin's lymphoma. Despite this, he continued to be involved in rugby league by volunteering as an assistant coach for a school's 2nd XIII team. Coach Mannie Navarro and his wife Ek were so moved with Simpson's courageous, selfless optimism that they later named their third son James Neal Navarro 11.11.2008 after Jamie. While hospitalised in isolation in late 2003,
Brisbane Broncos coach
Wayne Bennett gave him an autographed copy of his book ''Don't Die with the Music in You'' with a personal message: "Tough time comes and goes, but tough guys last forever" and was also encouraged to pursue a professional career by family friend
Scott Minto. Simpson was South Sydney's nominee for the 2009
Ken Stephen Medal for Services to the Community for his work in helping and visiting young people with cancer. ==Early career==