It's all about creating a back story for the character and developing emotional responses that are true to life in relation to the character. It isn't necessary to live a tragic life to create from that place.
I did private study for about a month, five days a week, six hours a day. I came to understand the character in ways that I never would've previous to that. I was so innocent in respect to ways of creating characters.
I have my ethics and morals. I have my anchor point of what is right and wrong in real life, but I'm not afraid to entertain any and every aspect of personality in relationship to creating a character.
I try to find what is closest to me in the character. There's many sides to personality, but it's a matter of, do you entertain those specific areas of your personality, or are you afraid to entertain them?
There were time when I was into method acting that I did have moments of residual character emotions, because the method bases your emotional responses as a character on emotional experiences from your real life.