In her final years my grandmother, who lived to 95, told me time and again "I'm ready to go!" (Once she scared the personnel at the assisted living facility because they thought she was suicidal!)
Rare diseases becoming more common could be the result of a) better communication and thus increased awareness, b) a larger population and thus more people getting such maladies, or c) yes, they are striking a larger portion of the population than before. These could be the result of all the toxins we have been pumping into the air, water and land for centuries. Regardless, they are terrible - but increased awareness will encourage more research into treatments and cures.
This probably goes all the way back to the womb, and why babies like to be rocked. It simulates the motion they experienced in utero when Mom was moving about.
It's fun to watch this and think about how much we have learned in the last six decades. Some of the information is woefully out of date, but it is still fun to watch.