Why is JavaScript’s ‘this’ Keyword So Different from Java’s?

The main reason is that JavaScript is not solely object-oriented like Java. In Java, everything is an object that inherits from `Object`, which makes `this` consistently refer to the current object. However, JavaScript has a variety of contexts it can run in—like functions or event loops—leading `this` to refer to different things depending on those contexts. If it were more like Java, we'd need distinct names for all those additional contexts.

It's important to note that JavaScript is a prototype-based language rather than a class-based one. Unlike Java's static structure, JavaScript's functions and methods are more dynamic—`this` changes based on how the function is invoked, which adds to the flexibility but also the confusion.

I think the original intention behind `this` in JavaScript was to make it more flexible. It may seem complex at first, but it's really just a different approach to handle context in functions. Other languages, like Python, do it differently with `self`, but JavaScript has its own unique reasons and history.

Interestingly, in a prior version of the language (ES4), JavaScript did have a more rigid approach to classes and `this`. They initially considered not having the contextual `this`, but ultimately decided on keeping the flexibility we have now, which aligns better with JavaScript's first-class functions.

Honestly, dealing with `this` in JavaScript can feel like a skill issue sometimes. With modern JavaScript, like arrow functions, you can bind `this` automatically, which makes handling it less of a pain while still maintaining the language's prototypes.