Typecasting helps. Certain actors have been typecast as certain archetypes over and over. Look at Anthony Hopkins as the teacher-archetype. In almost every movies he plays in, even his Hannibal Lecter movies, he plays the teacher-archetype. He has his pupil something to teach, and even only comes in the life of the pupil when he has something to teach, as he says in the zorro movie “the mask of zorro” (and my favourite movie quote ever): “When the pupil is ready, the master will appear.”
After watching hundreds of movies, I think I’m qualified to launch my movie theory on the world. My theory is this: When an actor has found his character, the one he is meant to play, he can’t play anything else anymore. I will give you examples.
Look at Rowan Atkinson. If you see him, you automatically see Bean. At least, I can’t see him in any other character than as Bean. You see his mannerisms in every other character he plays. The way he looks, the way he pulls his lip, the way he flaps his hands… everything.
Look at Johnny Depp’s acting career. Everything he has done up to Jack Sparrow, was just preparation for his one character: Captain Jack Sparrow. You see his mannerism, the way he looks in Edward Scissorhands. The full character was there, and he can’t remove him out of his acting anymore. Look at Sweeney Todd. The way he talks is still Jack Sparrowish. Look at The lone ranger and 21 jump street and you see mannerisms of Jack Sparrow in them.
I will post more when I have more one-characters.