Amusingly, I'm getting a chance to put that into practice right now. I'm playing an extremely tiny supporting role in my current play. I was actually up for the lead, but didn't get it. (I think they made the right choice.)

Before I had played a lead, this would be very frustrating. Having played leads, I now know what it is the lead needs from me, and I can be very important in my place. It's a useful demonstration of what a good actor can do without the script giving them a lot.

(I know that was a joke, but I thought it was worth noting.)