There is no magical day when you suddenly always know exactly what to do in every situation — there’s always more to learn. Engineers who have been at Google for years still have areas in which they don’t feel like they know what they are doing, and that’s OK! Don’t be afraid to say “I don’t know what that is; could you explain it?” Embrace not knowing things as an area of opportunity rather than one to fear.3
I like to illustrate this using a backwards-looking perspective: Do you actually ever want to look back on a year and be able to say that you didn't learn anything?
