really good acting instructors

is you learn how to use your facial expressions to change your tonality to trigger different emotional drivers

in the audience's brain that's watching the movie when you're watching jason bourne

you don't view him as jason bourne you view him as the character he's portrays because of his body language his tonality he's not just sitting there talking like this the whole time

through the movie and one monotone voice in the space just sets like this but because of his facial expressions and he's using different tones for different parts of the scene moving even in the same sentence he might say it draws you in

and it triggers different emotions with you