I recently re-read "To Kill A Mockingbird", because I am planning on reading "Go Set A Watchman" and wanted it to be fresh. I previously read TKAM back on 2004, when I was on a kick of reading "classics" that I'd never been assigned in school.
One of the key takeaways was consistently trying to think about things from someone else's perspective. I think most of humanity either forgets to do that, or is incapable, most of the time.
The world would be a better place if we started off thinking about the people that disagreed with us, and asking "why do they do so? how did they get there? what led to them reaching a conclusion that I disagree with but they sincerely believe is right?"
But that requires a level of empathy that I think is beyond most peoples' capability.