Actually, more... much more than you would think.
Backstory: A recent fictional article (Without Inspection by Edwidge Danticat) in The New Yorker began: " It took Arnold six and a half seconds to fall five hundred feet. During that time, an image of his son, Paris, flashed before his eyes."
Six full pages later, Arnold hit the pavement and died. That's about one page of his life per second... a lot to think about.
While the article is a good fictional read, the six written pages of Arnold's thoughts aren't at all unrealistic according to the research done on that time between awareness of impending death and the live mind. It takes a lot more time to read his thoughts than for Arnold to think them. And in this scenario, it is a really clever way to tell a compelling story.
Actually, if you are (or are not) a fan of television's The Big Bang Theory, the opening is a grand example of how to think back on 14 million years in 23 seconds, but then, that's technology for you. What your mind can do is even more mind-boggling.
This 'more-common-than-you-would-think' happening is scientifically studied as a Near Death Experience: "A personal experience associated with death or impending death." Neuroscience research says "... a NDE is a subjective phenomenon resulting from a disturbed bodily multiscensory integration that occurs during life-threatening events."
In other words, your brain says "Oh my God, what is happening to me?" and kicks into a state of hyperactivity and awareness allowing all sorts of things to happen in your mind. It is often referred to as "your life passing before your eyes' before you die... or fearing you are going to die, It is a state of hyper-awareness.
"What Are You Afraid of?" a column in The Atlantic magazine asks: "One reason we struggle with fear is that we're simultaneously too primitive and too evolved for our own good... Our brains are ruthlessly efficient. Signals speed to the threat-sensing amygdala ( two parts of the brain involved in experiencing emotions) within 74 milliseconds of the slightest hint of danger. This speed has, over eons, helped save us from extinction. But it's also led to plenty of false alarms." Maybe better safe than sorry, huh brain?
One man writes of his NDE which kicked in as his vehicle skidded on 'black ice' when, in mere seconds, he takes stock of all that is happening as he slides helplessly out of control on a crowded expressway. He reviews all of his options and projects who he might hit and where he might wind up, at the same time, turning to check on his young daughter riding behind him who, to his horror, has unfastened her infant seat belt reaching for some skittles, and moves to try to protect her while he fears they may slide into a guardrail--all in an instant. Post crash, they luckily avoided any collision and missing the guardrail, smashed into the hillside. Reflecting back, he is aware that he saw everything as if in slow motion, including his daughter's six skittles and that he can remember their individual colors and positions on the seat.
Mutter Museum in Philadelphia.)
Actually, comedian Emo Phillips has it right: "I used to think that the brain is the most wonderful organ in my body. Then I realized who was telling me this."