" the author claimed that blacking out wasn’t simply a matter of forgetting what had happened, but having no memories to forget in the first place. His theory was that you get into a state where your brain no longer makes short-term memories. And while you’re there, in deepest black, you don’t behave as you usually would, because you’re simply reacting to the very last thing that you think happened, because—since you aren’t making memories—you might not actually know what the last thing that happened really was. "

― Paula Hawkins , The Girl on the Train