Sticking with it.

There is simply no substitute for sticking with a problem long enough to receive and process the feedback generated through customer use of your systemLuke Hohmann
While this citation was made in the context of becoming a software architect, the statement certainly holds up in a broader context: If you want to become a master in your craft, you got to stick with it for a long time. All Silicon Valley start-up-build-1.0-burn-out-fast-and-switch-jobs-guys repeat after me: …for a long time…
I’m talking a significant amount of calendar years, folks. And make sure not to confuse “sticking with it” with “not learning new things”.