I learned WAY more after school (but a lot of this could be tied to my graduating in the early 2000s, when the internet was exploding with new forms of self expression and had not yet become completely dominated by algorithms and corporate capture). The problem with learning broadly is that eventually all the easy to grasp and explain, but stimulating and powerful ideas eventually become known. Then you either become interested in learning more obscure trivia, delving deep into a particular field (which is fine, but you've got to pick where to specialize) or instead prioritize other things.

Many people who spent a lot of time focused on learning decide that spending a bit more time on physical health is more important. Many have far less time as they raise families. Others determine that putting forth effort to more clearly express the ideas and knowledge they value (whether through discussion or art) is their duty, to make it easier for others to follow, and then perhaps take the baton further.

I spent a lot of time changing my mind about things because I listened and learned so much. I'm still open to doing so, but sadly, after a point you are so much more informed than "the average person" that there's diminishing returns to seeking out alternative views and opinions. And don't even get me started on the "Just read this four thousand page book" recommendation that some people make.