“Stop and smell the roses” is more than a good reminder. It’s good science. Our brains use more neurons to detect negative experiences than positive, and install them into long-term memory much more quickly. The reason? Evolution. In an interview with The Atlantic, Dr. Rick Hanson, a neuropsychologist, explains it was vital for early humans to learn from dangers such as predators or storms. You could go a few days without a positive event like finding food or mating, he says, but if you did not avoid the predator, you died today. Over thousands of years, that “negativity bias” was hard-wired into our genes.