I joined a professor as he rounded on patients in the adult hospital wards. As always, the patients we saw on the wards were quite sick, suffering from several chronic diseases with little chance of cure.
Although some patients were in a bad way of their own volition (alcoholism leading to liver failure, smoking leading to lung problems), some were there because of bad fortune. One patient's spine had been injured in a car crash when she was a teenager, paralyzing her legs, limiting movement in her arms, impairing her breathing, and leaving her incontinent of urine. Her impairments left her vulnerable to infection, and a particularly nasty one had landed her in the hospital. Just one car crash had altered her life's trajectory.
Another patient was a nurse with liver failure because of Hepatitis C infection. Although it wasn't clear how she contracted the virus, her exposure probably came from one of the patients she had cared for.
Why were myself and the physician the ones in the white coats and the patients the ones in the beds? In large part, because of chance. It boggles the mind.