"Why some anxiety is good, even though it feels bad"

I was listening to the NPR program "On Point" and the topic was anxiety. Anxiety as an emotion brings data about uncertainties in life. The key is how we can use it wisely, developing life skills.

*Excursus 

1) Anxiety is an emotion caused by uncertainties in life.
2) Stress is extreme tension/feeling caused by one's situation that one can hardly find options to deal with it. 
3) Affliction includes all kinds of hardships, tragedies, and difficulties in life.