Interest rates have always been central banks' go-to weapon. But here's the thing—as populations worldwide get older, this tool might just stop working the way it used to. The demographic shift is real, and it's forcing central banks to rethink everything. They can't rely on the same old playbook anymore. What's next? Finding fresh approaches to steer through an increasingly unpredictable global economy. The traditional levers are losing their grip, and policymakers know it.