If you wish to learn ES6/2015 from scratch, you must first invent the universe: Ashley Williams, JSConf 2015
Holy wow. This talk is instantly in my top 3 favorites. Funny, intelligent, thought provoking, and it provided me with some solid vocabulary for a lot of the things that have bothered me about various language features but I was never really sure why I felt that way. Things that I was intuiting now how solidity to them. There’s also a great bunch of references to various books I now have to go hunt down.