It always amazes me that young people who perform in plays, especially at the high school level, seem to learn very little about their plays. Sometimes they don't know the simplest things. For instance, when paraphrasing "All right," if the play is set in any time period before WW II, you can't say, "OK." It is an anachronism. In the 1950s, people did not make little quotation marks in the air to indicate a quote.
In the 1970s, we began to wear our jeans dragging on the ground. Never before, in the history of trousers, have people worn them that long. Therefore, if one is playing a character in a play set in the Civil War, or the Great Depression, or the 1950s, one's trousers need to be shorter.
Theater offers us such opportunities to learn about other cultures, other times, other customs. It shortchanges the play, and the audience, and the actors themselves, to neglect this basic research.
There is a lot more to acting than memorizing lines and taking direction.