The trick to taking over the world is just this: keep moving.
First, you have to survive the apocalypse, of course. That’s mostly chance. An earthquake, a mudslide, a flood . . . you take what you get. Then, you get your wits about you—if you can, as best you can—and then . . . you move. In a disaster—particularly a world-ending, catastrophic disaster—people are drawn to anything that moves. They want to move with you. They want to get away from whatever just happened. They want to get on with their lives, even while the world is ending. They want to do something, but they don’t know what or how. All you have to do is move, and the lost, broken people around you will stop sitting in the rubble, and move with you. And—as it turns out—when the world’s in pieces around you and still falling apart, motion is two-thirds of survival. Things that sit still for too long get crushed, get sick, get eaten. They die. The people who followed you? Well, they look back at all the ways they could have died and didn’t. Proof positive you know what you’re doing. You keep your mouth shut, and keep moving. They’ll keep following, because you’re the leader, now.
They trust you.