I'm currently reading "JavaScript: The Definitive Guide" and it's a mighty long book because it basically covers EVERYTHING related to JavaScript. This has got me wondering: Am I wasting my time by learning the granular parts of the JavaScript language?

For example, JavaScript has this concept of a positive zero (0) and a negative zero (-0). Both values are equal in JavaScript, except when used with a divisor:

var positiveZero = 0;
var negativeZero = -0;
positiveZero === negativeZero; // => true
1/postiveZero === 1/negativeZero; // => false

Let's be real, what are the odds of me remember such odd behaviour and what are the odds of that ever being useful while working with JavaScript?

What do people think? It's it worth spending time learning such obscure parts of the language. If not, is it worth reading books that go into the real deep parts of a language?