The song is a first-person account of a typical Australian soldier's experience in the Vietnam War, from training at Puckapunyal army base in Victoria to first hand exposure to military operations and combat, and ultimately his return home disillusioned and suffering from both PTSD and, it is implied, the harmful effects of Agent Orange.

[10] Redgum's lead vocalist-guitarist, John Schumann, wrote the song based on experiences he heard from veterans, particularly Mick Storen (his brother in-law) and Frankie Hunt.

[11][1][4] Schumann has said that "the power derives from the detail, provided by my mate and brother-in-law, Mick Storen, who was brave and trusting enough to share his story with me.

"[22] Frank Hunt provides an account of his Vietnam experiences, titled "I Was Only Nineteen", in Gina Lennox' book Forged by War (August 2006).

[23] After Schumann had received letters of request from active soldiers in Afghanistan and East Timor, he sought permission to visit the troops but obtained no answer.

[24] A reporter published an article on the situation, and authorities gave permission for Schumann to tour East Timor in December 2009 and entertain Australian and New Zealand troops.

Australian country singer John Williamson recorded a live version as "Only 19" and released it on his 1984 vinyl LP, The Smell of Gumleaves (rereleased in 1996 as a CD under the title Home Among the Gum Trees).

[33] The song's and album's producer, Trevor Lucas, performed his version as a member of his United Kingdom-based group Fairport Convention at the 1985 Cropredy Festival.

[34] On the show Fast Forward, Gina Riley, in character as Eleanor LaGore, performed a swing version of the song.

[36] After COVID-19 had hit Australia, several musicians created a parody of the song, realising the lyrical similarity of "I was only 19" and "It was COVID-19" as well as the shared macabre nature of both topics.