Left hands are taboo. Given that I’ve encountered this exact taboo multiple times before in the Middle East and Asia, you’d think I’d have it down by now, but I messed up at least five times by doing things like touching my food with my left hand or handing something to a person using my left hand, getting scolded for doing so each time. The idea is that people there use their left hand for all things dirty, and the right hand is kept clean for things where cleanliness matters. And after spending a four-day stretch in a rural area with no access to soap of any kind, I understood why this wasn’t just for the hell of it—it was an important health practice.