23 problems carry a brand-new problem

Not all problems are ancient. Some were created within recent memory — by a new technology (drone traffic, AI-generated content), a new regulation, or a sudden event. New problems have a distinctive character: there's no long record of failed attempts to learn from, few entrenched assumptions, and often no incumbent field that owns them. That makes them unusually open territory — and unusually easy to underestimate, since no one has mapped their edges yet.