There's something special about watching someone do something that they were born to do. It fills us with awe, excitement, inspiration, encouragement etc.. At the core of who we are as humans, there's a recognition of that "something special" - that spark that a person holds up for the rest of the world. They were clearly born for this and we find joy in getting to see them do it. You've seen it - you know what I'm talking about. It's easy to see it in people who are on the w