var self = this;
The only possible value it might have is when nesting functions if you refer to `self` instead of `this` correctly, but this is the only case when I actually use this pattern, and when I first create a nested function that needs to use the parent's scope. Another option is to just `.bind(this)`.
In any case, I would disagree that one should try to avoid `this`. Instead, one should educate themselves to understand what things in the language they're using mean. And this subject is a great weeder question in Web Engineer position interviews. If a person can't implement `bind`, can't explain `call`/`apply`, what strict mode does, and what the `this` keyword means in most contexts, they probably aren't strong enough in JS. This is one of the most fundamental concepts in JS, it shouldn't be a source of confusion.
Dereferencing things that aren't pointers leads to unexpected results in C. Should we avoid dereferencing any variable in C?
I think of `this` in the same way - it behaves normally if you use it the way it's intended to be used. In other words, don't try to read `this` in a callback without binding it first, and you'll be fine.
Or are there other pitfalls I'm unaware of?
And btw, the `this` situation with javascript is not that bad :) use bind - either the Ecmascript 5 version or shimmed and you will be fine. Not much drama.