Matheson, who serves with Mississauga Fire and Emergency Services and as an officer in the Governor General’s Horse Guards, later travelled to New York with fellow firefighters to attend the funerals of the fallen. He recalled seeing the strong bonds between Canadian and New York fire crews as they mourned together.

The experience made him aware that the shock of 9/11 was not limited to the victims on the ground. "I realized how much trauma we, as responders, can carry," Matheson said, noting that the event highlighted a gap in mental‑health care for those who routinely face danger.

Motivated by that insight, Matheson began volunteering for the mental‑health charity Wounded Warriors Canada. He explained that, since 9/11, support services for both military personnel and first responders have improved, but there is still work to be done.

During the 25th anniversary of the attacks, Matheson joined a Wounded Warriors fundraising bike ride that traced Canadian World War I battlefields in Belgium. While riding, he reflected on how far mental‑health programs have come and why continued investment is essential.