Last summer, Tobi A. changed my life by telling me about a martial art that he had been learning called Brazilian jiu jitsu (“BJJ”). I had 0 experience with martial arts and, transparently, I was disinterested in such a seemingly violent pursuit. I’ve always considered myself an athlete and had been playing a ton of soccer and tennis but fighting as a sport never occurred to me as something that I’d like or that would be sustainable long-term for my health. However, Tobi described jiu jitsu a...