Most generally, people are smart, but sometimes they make simpletons of themselves.  Humans don't, on purpose, do things against themselves ... if they're in their right mind. 

It's when our minds are perverted and influenced by the devil that we do stupid things that hurt ourselves ... and others. 

This is all in the natural soulish realm ... not in the spirit.  When our minds are influenced in this way, we go and do the same things over and over again.  It's a cycle ... until we meet Jesus and He changes us. 

First you make Jesus your Savior ... then you make Him Lord of your life.   

Reverend Robert W. & Mary C. Butler