They don't parrot if you know what to ask for. You can name for examples, name your own thoughts and observations and these things will often quote something related or the fact that a famous mathematician has also made this observation some point in time which then lead to the study of something else.

I am not going to study a whole book just so I can find the answer to a couple things I might never need. I like to focus on a few areas, learn everything I need to understand it, know if there are any dependencies and see what is there to discover and then move on.

I know many people get joy from learning knowledge that is not directly applicable and might never be applicable. And I know that the academic spirit would be to learn these things. But my time is seriously finite and I am not using math in my life in any fashion whatsoever other than occasional curiosity.