I don't think I ever learned what Benedict Arnold did until my college history class. The high school class just covered the basics, but that was one big omission.
college history pretty much just spents the entire time debunking the myths feed to you in grade school. in fact i think the only useful think i learned in high school history was the 2 rules for taking over europe.
1.) you need a boat to get to england.
2.) do not, i repeat, do not invade russia in the winter.