I'm fascinated (and horrified) by ironic extremes: physicists who develop Alzheimer's; orators who can't speak after a stroke; athletes who develop crippling disabilities.
While visiting a nursing home recently, I met a man named Gary. He'd spent his career trimming trees, navigating the canopies of the tallest elms, willows and maples. Never an accident, but he'd often noticed people watching him from the ground -- surely thinking, and sometimes even calling out, "Don't fall!"
Now, rehabbing from a stroke, he walks the hallways between his sleeping room and the dining room. He notices the nurses watching and he can almost see their lips move: "Don't fall."