It really is nothing nothing nothing and then suddenly.
Whenever I feel that impression inside myself, I always question it. To the casual observer, i.e., those who are not “paying attention to objective reality left and right”, that’s how things often seem, and even though sometimes things do just come out of the blue, most of the time, what seem to be large and surprising events have long preludes which could have been anticipated if we were paying enough attention and which make sense when placed into the larger context of how things tend to work in our reality.
In other words, it’s never just “nothing nothing nothing”, there’s an infinite amount of ‘somethings’; it’s just about how we learn to sort through those ‘somethings’ and figure out which ones we should be paying attention to.