Most near-death experiences can be easily explained, chemicals getting sent to your brains to stop you from the pain or your body 'shortcircuiting'. The reason why many people see it as the same things is probably because it's an image that was put into your mind of how it should look like. Similarly, if you let someone imagine an alien, you'll probably get something along the lines of little green men or atleast something that still looks pretty human.

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