Grant was something rare in that or any war. He could learn from experience.
experience learning mistakes
I think that everything you do helps you to write if you're a writer. Adversity and success both contribute largely to making you what you are. If you don't experience either one of those, you're being deprived of something.
adversity experience help success writing-life
But the same thing was true in the army. You slept in a barracks with all kinds of people of every nationality, every trade, every character and quality you can imagine, and that was a good experience.
character experience people quality