Further on the “list of things I should have realized but didn’t”, if you are working through a course at Codecademy and get stuck, you can’t continue, and they don’t give you a solution. In order to find a solution when I was stuck, I discovered people are broadcasting themselves going through the classes on YouTube! It’s a great way to watch someone else struggle with the same thing you are (and get a hint). Note, they may be doing it on Twitch.tv too, but I didn’t check.
2And even if there was one, it may have been beyond me, to be fair.