Robert Mitchum cultivated an image of not caring, describing acting as a job with better hours than most, and used the resulting stillness to devastating effect. The heavy-lidded delivery reads as boredom until you notice how little he wastes.
Out of the Past is the noir performance, narrating his own doom without apparent alarm. The Night of the Hunter and Cape Fear are the villains, and the Hunter preacher with LOVE and HATE on his knuckles is among the most frightening things in American film.
He was jailed briefly for marijuana possession in 1948, which the studios expected to end him and did not, partly because the persona survived it comfortably.
He worked constantly for fifty years, in a great many films that did not deserve him, and never appeared to mind.