Liam Neeson based his action hero character in the Taken movies on the real-life weapons expert who helped train him for The A-Team.
The Irishman admits he was left stunned by the adviser - because he'd disappear for days to fight terrorists and then return to the set wounded but ready to go.
Neeson never complained about the hard work because he quickly realised the guy advising him lived a real hero's life.
The actor tells U.S. interview show Inside the Actors Studio, "I can't use his real name because I don't know his real name... He'd be training us and suddenly he'd disappear for four days, and he'd come back with wounds in his belly, wounds in his shoulder, wounds in his leg - and he was in Afghanistan doing something... and then he'd be back on set getting vitamin B-12 shots.
"This happened three or four times during (The A-Team) shoot... and he kind of inspired this guy (his character in Taken)."