Should an actor practice being in character in public places not on stage?

It is absolutely wonderful when someone asks a really good
question. This evening I was asked if
an actor, in order to better play a character not like himself, should practice
being that character at home, or in other places out side of the theatre. The following is an edited version of my
reply:

Not at all; that is
nonsense. You should keep your acting and your character on the stage. To act
or try to be your character off stage is not only rude to people around you, it
could be interpreted as mental illness. Theatre and cinema exist, so we can feel as important, attractive,
charming, and brave as we do in our imagination. But we must not try to be in public what we imagine ourselves to
be in private. (Read Theatre, Religion,
and Football, an article on my web site under Acting Theory.) Neither us, nor
the actor, nor us as actor are the character. The character is a fiction
created by a playwright. (Even historical characters must be somewhat
fictionalized in plays and films.) The character only exists in the
imaginations of those who read the script. That is until an actor takes the
place of the character on stage or in front of the camera. When the actor does
that he establishes the physical part of the character, the walk, the gestures,
the posture and the voice (if they need to be different from his own--which
they often do not). And he represents the character for the audience to see and
hear. The vast majority of casting of actors in roles actually want the actor
to simply look and sound like himself when playing the role. (Once, I was
playing the next-door police detective in "The Gazebo." The director
said to me, "Ken, stop doing all those character bits and just be yourself
and be charming." It was the most
difficult acting assignment I had ever been given. I did not consider myself as
being charming, so I had no idea what to do. I had not yet learned that it was
important not to "act" the role. It is the actor's job to simply
stand in for the character, and the actor does not have to make up a lot of
gestures or plan facial reactions. Rather than pretending, the actor allows
himself to have full and honest emotional responses (his own, unplanned
emotional responses, pleasant and unpleasant) to the stimuli of each moment of
the play as it occurs. He does not pretend to feel or pretend to respond. He
feels and he responds. So you don't need to practice being the character off
stage. The character does not exist off stage. He only exists in the imaginary
circumstances of the play and no where
else (except in the case of historical or real people as characters). So you
stop representing your character when the director says "cut," or if
the play or scene ends. Keep your performances fresh, spontaneous, and
vulnerable. And keep them only on stage.