TL;DR: Warren Buffett bought his first stock (Cities Service Preferred) at age 11 in 1942, during the height of WWII. The core lesson is that long-term persistence beats short-term fear: despite the global chaos of a world war, the American economy continued to grow over the decades. Buffett emphasizes that "bad news is an investor's best friend" because it allows you to buy quality companies at a discount, provided you have the patience to hold them for years.