Note to Self: Mistakes were Made...

I've known about this for years, but there is a way to turn off the keyboard on a laptop. About once every 3-5 years, one of my cats walks across my laptop and the whole keyboard goes dead except for a couple of navigation keys and the Fn keys. 

Maddening. 

Since it doesn't happen that often, I never remember the keystroke necessary to fix it. 

For the record and for the next time, the keystroke is Control+Alt+L.