One way to aim high is to try to make something that people will care about in a hundred years. Not because their opinions matter more than your contemporaries', but because something that still seems good in a hundred years is more likely to be genuinely good.
There is a tension; the longer you remain committed to a single cause of greatness, the more incapable you become of being good enough at everything else.
I asked Kelly about the tradeoffs of focusing on a single thing if you want to be great (which is what I had been getting at before). “Greatness is overrated,” he said, and I perked up. “It’s a form of extremism, and it comes with extreme vices that I have no interest in. Steve Jobs was a jerk. Bob Dylan is a jerk.”