It does seem that a lot of people travel with a cloud over them. They allow hate and envy to rule their lives and they are miserable and unhappy people who seem more susceptible to getting sick.
As for why young children get sick, don't have an answer for that. Not saying a positive attitude will keep you disease free and make you live forever - in fact, we know that cannot be true. However, life seems to go much better when you have a positive attitude and eliminate negativity from your life as much as you can.
One of the hardest things to do is to disassociate yourself from people who are overly negative. But I've learned to walk away from people (or tune them out) who constantly complain, gripe, and have the "woe is me" attitude.
It’s not new age at all...and is becoming main stream because it is so effective that it is saving troopers from ptsd where they simply could not be helped before.