Haruki Murakami on the difference between inevitable versus optional:
Pain is inevitable. Suffering is optional. Say you’re running and you start to think, Man this hurts, I can’t take it anymore. The hurt part is an unavoidable reality, but whether or not you can stand any more is up to the runner himself. This pretty much sums up the most important part of marathon running.
I often think about Murakami’s marathons with regard to “busy.” Busy is inevitable most of the time, yet everyone just has a different threshold for it. Those who push past a particular threshold, who start to think, I can’t take it anymore, but are committed with every ounce of their being to an idea, they keep running, keep going — their unavoidable reality just isn’t optional.