Gwak Jae-u was a failed scholar who became the Red Robe General overnight

This guy failed every civil service exam he took. Total academic washout. When Japan invaded in 1592, Gwak Jae-u sold his entire estate, bought weapons, recruited local farmers, and formed a guerrilla army. He wore a red robe into battle so his troops could always find him — and so the enemy would know exactly who was wrecking them. He dominated river battles along the Nakdong using local knowledge that the Japanese couldn't counter. No formal military training whatsoever. Just a failed test-taker who was really, REALLY good at improvised warfare. Mans literally went from 'unemployed intellectual' to 'legendary guerrilla commander' in like a month.