I disagree, knowing the good parts about JavaScript isn’t difficult. What’s more difficult is being able to explain the bad parts about your main language. And

I disagree, knowing the good parts about JavaScript isn’t difficult. What’s more difficult is being able to explain the bad parts about your main language. And JavaScript has quite a few, if you’re not able to highlight those, I wouldn’t consider you an expert at all. By knowing all the bad parts, you’ll be able to write much better code, because you know what to look out for.