Nearly two decades ago, while working as a researcher at the University of Derby in England, Miles Richardson started taking daily walks to recover from long days behind a desk. Around the same time, he got his first iPhone and began using it to jot down notes about everything he noticed on those outings—from birdsong and budding flowers to shifts in the weather and changing seasons. After his first year, he had amassed some 50,000 words of observations. “That had quite a profound impact,”