I went anyway.

The training was conducted by Wayne from Disaster Survival Skills, LLC. Disclosure: I have no interest, commercial or otherwise, in this company. The training was from the perspective of schools and our ability to help staff and students survive the "Big One." He reviewed light urban search and rescue techniques and procedures, basic lifesaving (breathing, bleeding, shock), mass casualty events, public utilities shutoffs, evacuation, SEMS, and personal preparedness. Because I'd taken the extended course, and I work diligently on preparedness and survival, none of this was new. But it was a dizzying review of things I hadn't thought on in a while.
The scariest part to me is that a Magnitude 7+ earthquake (a regional "Big One") hits every 45 to 144 years, it's been 150 years since the last mega-quake, and there is a 99% probability that a major earthquake (in the 7+ category) will hit the San Andreas Fault any time in the next 30 years. It will be the largest natural disaster in recorded American history. In that case, the ground faults will exceed 8 feet of movement, which means natural gas and water pipelines will be ripped apart underground. The presenter estimates that it could take 3 MONTHS to restore gas, water, and electricity to pre-quake conditions. In other words, he said, if you live in SoCal, you need to be prepared to be without natural gas and water for 3 months. In a worst case scenario, the entire San Andreas fault gives way, resulting in an unprecedented 9.0 earthquake. Nuclear power plants are rated to withstand a 7.0 quake. Anything in excess of that and we'd better put on our lead undies.
I'd always heard 3 days, but holy God was this a wakeup call. I'm prepared for one month of food unassisted, and 15 days of water. I have unlimited first aid and basic lifesaving equipment, and a year's worth of candles, matches, and so on. But 3 months without water? It's time to speed up my acquisition of two 5-gallon gravity filtration systems, and more ammunition.