Something happens, and then you choose what to do about it. The space between those two things is where character shows up. A pause of a second or two lets your body settle enough to answer instead of react. I am not especially good at this. I lose my temper like anyone else, though I do think practice has made me better than I used to be.
This is the short version. The full lesson, with the story behind it, is in the book.
Take The Summer Camp MBA with you, or get the field notes by email while you work through the lessons here.