Something that surprised me about Java is that it's not just "Object-oriented", it's straight up entirely class-based.

Everything in Java is written as classes, attributes and methods.

Even the main function is just a 'main' method on the programs 'main' class.

You want to define a function that just transforms something without being related to an object? Still gotta be a method on a class! (Though at least that part results in familiar syntax where you can just import that class as if it were a library/package with the class name as the 'library' name.)

Now I'm even more curious about what strange logic must be inherent to functional programming languages if this is what a fully object-oriented one looks like.