I recursed through the State and Lifecycle article in the React docs, as I figured out how yo fork code snippets on Codepen. I rebuilt the clock app in pure JS. Having done that, I continued on to learning about Handling Events with React, where I got tripped up on the binding of 'this'. I was confused as to why a method needed to be bound in the "onClick" example and not the "clock" example. After some review, I realized that the "onClick" example used a function to update the UI, whereas the "clock" example automatically updated the state. So much to learn.