Creepy long-read on the science of surgery patients who wake up during anesthesia

I have breast cancer, and I am going in for more surgery tomorrow. Awakening, by Joshua Lang in The Atlantic, may not have been the best choice for pre-op reading material, but it is a fascinating piece. Read at your own peril if you're planning on a trip to the O.R. any time soon. The tl;dr: tens of thousands of patients each year in the US slip out of anesthesia and regain wakeful consciousness during surgery. They can't alert anyone, and they suffer PTSD in high rates. What does it mean to be conscious? And how can this phenomenon be prevented?