I've saved this one for last because it was overwhelming both in scope and content. The presenter was Ben Falk of Whole Systems Design but the workshop was not specifically about permaculture.
Instead, he started with a list of catastrophic things that could happen, touching briefly probability (alien invasion vs. pandemic). Then he began covering a list of items and skills you might want in place in such an event.
Some things were obvious, like hand tools and the knowledge of how to use them. Other things would not have immediately come to my mind, like gravity fed water.
I feel like he tried to stay relatively light, but his topic was naturally a bit depressing and scary. My sense of "hurry, hurry" to learn how to grow a variety of food and to enmesh myself in my new community is heightened. I want to have a small generator on hand. I want to be somewhat comfortable with a gun. I want to know how to take care of cows and find a resource for hay. I want to get fruit trees planted and get the pines down. I want to plant some trees that can be coppiced for firewood. And so on. I do not even enjoy reporting on this seminar, but I think it was important.