Nobody warned me about the streets. I landed in Kigali expecting to be moved by a memorial, and I was, but what caught me first was a city with no cigarette butts on its pavements, no plastic bags in its gutters, orderly traffic and a simplicity that made everything feel calm and deliberate.In 1994, Rwanda was devastated by a genocide that killed more than one million people in one hundred days and tore the country apart. Thirty-two years later,…