It's not like you'll actually use it for anything useful, but hey, it's a good way to waste a few hours a day.
You could learn about data structures and algorithms, but who needs those when you have Google?
Or, you know, learn about object-oriented programming, but who needs to make their own video games when you can play someone else's for free?
But seriously, if you're still interested in learning, here are some reasons why you shouldn't.
Why Not Learn Javascript, You Ask?
It's not like anyone actually reads this page, so what's the point?
You'll only end up writing code for your cat's online shopping list.
Or, you know, for that one friend who's always asking you to "just fix this thing for them" and you're like "no, I have better things to do".
But hey, if you still want to learn, here are some reasons why it's not worth it: