You can't learn every library or every tool but you can learn how the language actually works. For example, if you think JS has floats and integers, you have so

You can't learn every library or every tool but you can learn how the language actually works. For example, if you think JS has floats and integers, you have some reading to do. If you think "array" is a type, take heart, because you can learn why that's not correct. If you can't decide whether to use Ember or Angular, maybe you can grasp how closures work. Before React and Redux and Gulp and whatever else, understand how the language works. Pretty please.