Be true to your characters and they'll be true to you,
This is advice to the author, but it can be equally applied to the actor.
One day I performed a scene for a directing class at a well know theatre school in New York. The teacher of the class was ill equipped to teach. He knew next to nothing about directing and, apparently, nothing at all about acting. He wanted the character I was playing to "do nothing." Actors do not go out on the stage and do nothing, that's not what acting is about.
Twice in my career I played men I did not like. Playing heroes and villains is fun for an actor. If the play is good the author has given you the tools to express your own inner heroism, or to dig down and find the potential villainy in yourself. But to play characters that are neither good nor bad but appear on the surface to be inane is a real challenge.
The first time I faced this problem was on a soap opera. I played a doctor who was treating a baby girl. He had absolutely no compassion for the little girl's parents. He was cold, clinical, professional and uncommunicative. It was important to the plot that he be that way and so that's the way I had to play him, truthfully. But it wasn't "nothing."
The other time it was a play in which one character was written with many clever and funny lines and the opposite character was not. I felt that the part was underwritten. But he was a man of few words and had his own strength. I didn't like the guy but I played him truly. I know that because the playwright came to see it and went out of his way to thank me for my performance. He had, after all, been true to his character and so had I. I never did really like that character but I must have played him well because I was hired to play him three times at three different theatres.
The theatre is allegorical, yes, and part of the story is that life is action, ever changing and usually not what it appears to be. But the only way to safely rudder through it is to be active and alert and shun its inanities. Being true to our own characters is essential, even though it means looking behind the masquerades we have written for ourselves and facing them without fear.
As Shakespeare put it:
This above all: to thine own self be true,
And it must follow, as the night the day,
Thou canst not then be false to any man.
(Ease into winter, if you can.)