This document summarizes the key topics covered in a CSSDevConf 2016 presentation titled "Knowing it all" by Rachel Andrew. It discusses how the role of front-end developers has evolved over time from basic HTML and CSS skills to now encompassing a wide range of technologies and best practices. The presenter emphasizes that it is impossible to know everything and that front-end developers should focus on mastering core skills before diving into new tools and techniques, and should contribute back to the open web platform by engaging with standards bodies and browser vendors.