The second lesson after hard work is focus. I happened to know a few actors and actresses (no Hollywood stars yet) and I am always impressed by their high level of concentration when they are focused. Come to think of it, it all makes sense. It takes hours if not days or weeks or months for them to rehearse their roles. When they are on the set (either on stage, TV, being filmed), they need to perform their very best at that moment. A director will not be happy (and you will soon to out of a job) if you waste his/her money (filming is expensive) and time.
That high level of focus, concentration and professionalism is very important in all lines of business. Let us do our best when it comes to our ‘act’ and not waste resources nor time of others and our very good selves.