Comments are bad for a few hours normally . One time a post was made about a massive reduction in infant mortality in some poor African country comments were going on about what a great shame that is . <| sep |> Either way you ' re jumping for joy . <| sep |> I am not sure at which point in the FCC curriculum it was , but it was at the time I started implementing FCC calculator project . The mistake I did at the beginning was that although I listened to the JavaScript Understanding the Weird Parts and made notes , I didn ' t understood all the functional stuff . You need to use these concepts in your apps to be able to understand them properly . I guess the best way to learn this advanced stuff is to watch read , code and watch read again . I was able to understand scope and closures fully when I watched the course second time . I guess this is because this course is very robust and when you watch it for the first time you simply cannot absorb all the new stuff at once . Hope this helps