Those can be understood from a high level point of view in a few minutes time. I've sat through multiple classes that have done just that. Java is so deeply OO

Those can be understood from a high level point of view in a few minutes time. I've sat through multiple classes that have done just that. Java is so deeply OOP that there's just no way for somebody to grasp and understand the concept of e.g., a public method when they haven't even learned about variables or basic conditional logic yet. A total novice just plain isn't equipped to handle some of the concepts that are immediately thrown at them with a simple hello world.