When I was in 5th grade, my teacher did an anti-smoking schtick for a while (we had one every year) and cited life expectancy. I raised my hand and legitimately asked, "How do the doctors know when I am going to die?" No answer
"Ah, those endless forests, and their horror-haunted gloom! For what eternities have I wandered through them, a timid, hunted creature, starting at the least sound, frightened of my own shadow, keyed-up, ever alert and vigilant, ready on the instant to dash away in mad flight for my life. For I was the prey of all manner of fierce life that dwelt in the forest, and it was in ecstasies of fear that I fled before the hunting monsters."
Jack london, "Before Adam"