Ask HN: How do I learn JavaScript after using it for years

After using it professionally for quite a while now, and going through some weird process resembling the stages of grief I decided it's past time to learn the language.

I first started using it and I thought it was a horrible language. I kept using it for basic scripting tasks and I still thought it was a horrible language preferring to do most of the application logic in the back end. I learned some degree of AngularJS and used it in quite a few projects while complaining about how this would be so much easier in other languages. Now I have a project where we used JavaScript exclusively and the more I dig into the language the more I realise that you can do some really cool stuff in it if only you put in the time.

A stark realization hit me like a cannon: JavaScript isn't a shitty language, I'm a shitty developer for never bothering to learn properly it and writing it off.

Having decided to learn JavaScript I thought I would ask you all for advice on books/courses/anything in between. The only condition would be that it focuses completely on the language itself and touches no frameworks, just pure JavaScript. Bonus points if the book is relatively newer and touches on ES5/ES6 and maybe ES7.

Any help is greatly appreciated.