The question many actors (especially method actors) ask themselves to help them perform in the most realistic way possible.
Sometimes an actor is unsure about his motivation and asks the director, "What's my motivation?"
The answer varies from director to director, depending on how the director views his own job. Some will tell the actor what they think his motivation is. Others will outright refuse it as they believe the actor should be able to answer the question on his own, and keep it to himself. Indeed, occasionally the director's answer is, "Your paycheck!"
Not all acting teachers teach their students to answer this question. For example, my own teacher told us the most important question we need to ask is "what is my objective?" She also told us the director would never tell us what to do because it is not his job to teach acting, but to direct actors who already know how to act. According to her, the director will just say, "This does not work, try something else."
But, never say never. I have had a director who completely disagreed with my teacher. He feels it is his job, and part of the enjoyment of his work, to help an inexperienced actor learn what to do. Indeed, shortly before the opening night of Anastasia he told every single cast member what his motivation was. It worked, too.