Look at this generation, with all of its electronic devices and multitasking. I will confidently predict less success than Warren, who just focused on reading. If you want wisdom, you'll get it sitting on your ass. That's the way it comes.
We all are learning, modifying, or destroying ideas all the time. Rapid destruction of your ideas when the time is right is one of the most valuable qualities you can acquire. You must force yourself to consider arguments on the other side.
It's bad to have an opinion you're proud of if you can't state the arguments for the other side better than your opponents. This is a great mental discipline.
You must have the confidence to override people with more credentials than you whose cognition is impaired by incentive-caused bias or some similar psychological force that is obviously present. But there are also cases where you have to recognize that you have no wisdom to add—and that your best course is to trust some expert.