Something I figured out very early: if you know the basic textbook material about a subject with a passing familiarity, you know more than 99.99% of people about that subject. And if you can read and understand post-grad textbooks in that area, you know more than 50% of even experts in that field. It’s unfortunate but it’s true. Most experts are fairly mediocre.
That’s the reason I’ve read hundreds of textbooks. I wanted to avoid the dipshit version of doing my own research and instead actually do it for real. And I spent a large part of my life working on that. Paid off, too.