Street smarts beats book smarts.
Not exactly the lesson that I take from it. In life you need street smarts, book smarts. Soft skills and hard skills. However, competence is more important than mastery. Competence matters nearly all the time, it's the difference between being able to do something yourself and needing someone else to do it for you. It's also the difference between swallowing bad information and averting mistakes. Mastery matters too, but takes much longer to achieve and it's less frequently a benefit. It also makes you less flexible, because the particular skill may one day cease to be relevant. Usually mastery is key when you don't just need to be good enough, you need to be better than nearly (or absolutely) everyone else. For most people that's rarely going to matter, but if you're a F1 race car driver, it matters every day.
Most of the time, most people should pursue competence in many areas over mastery in few. If you pursue mastery, you should have a particular and good reason for it.