I learned: it's always best to completely unplug anything you value, before the lightning strikes.
Very true. The counterpoint to this is that you can't always be home when these events happen. If I am home, or know a big storm is coming I turn off my hifi system, but I have too many devices around the house I cannot do this for every time. Computers, networking infrastructure, TV in the bedroom, Wifi enabled light switches, thermostats, etc.
I take the belt and suspenders approach. Surge suppressor in the panel, and at the devices as well as network surge protectors on either side of the cable modem and I'm about to install a 3' air gap using fiber optic cable between the cable modem and the rest of my home infrastructure.