When you (inevitably) make a mistake, own it and learn from it – but never lose sight of the fact that the mistake was something you did and not who you are.
In other words, you either failed to do something you thought you could do, or you failed to execute something you knew how to do – both of which provide an opportunity for growth.
But understand the mistake was a temporary glitch that you will learn from and move on.
You are not the mistake.