In the film, the actor plays an AIDS patient Ron Woodroof and he was deeply touched when his character had to admit that he was "dying".
"My most surprising moment during filming was when Ron says, 'Look, I'm dying'. Saying that word, 'dying' floored me. To face that not as a concept, but as a reality," Bang Showbiz quoted McConaughey as saying.
McConaughey has also earned his first best actor Oscar nomination for the role.