The reason is the medicine they have taken. Doctors tell us that around four million people every year go into hospital in the USA because of their medicine. They're ill because of modern drugs and their side effects.
Some doctors say that the continued use of drugs has long term effects.
It has the effect of weakening the immune system. Today we have to do something about shyness. You have to be pushy to get on these days. You have to market yourself. If you want to have a career, you have to speak and act confidently.