go anyplace to people watch, and practice dowsing. with the finger dowsing, you can have your hand in your pocket and test. There are alot of sick people that don't even realize they are sick (yet). By the time things start showing up on medical tests, it's a full fledged problem.
"Ignorance is bliss"..wherever that saying came from.
I still remember sayings my G. Grandma told me when I was a child.