Reb Shamhon Rafael Hirsch says in Horeb, Section 1 page 10 " Both Minus and Zenus lead to idolatry - riotous enjoyment leads to it directly; denial and misrepresentations
of G-d usually over the bridge of pleasure.  For as soon as enjoyment becomes the object of your life, you no longer regard yourself as belonging to the world but the
world as belonging to you, and you know no law buy your own capricious impulses.  From that moment, you will no longer understand what is meant by unselfishness,
you will see in every creature a being which only obeys itself and works only for itself. "

"There is no more effective protection against the danger or deifying the creature than a proper self-appraisal, than being completely permeated with the consciouness of your own task in life."


Zenus leads to selfishness and the way to fix it is by doing self appraisal. 

Elya

Very teif

Not just that we ARE no longer unselfish but that no longer UNDERSTAND unselfishness.

2 diyukim:

1) we can be so self-centered as to not even comprehend that others are not the same way (makes it easy for to have so many times I can imagine that my wife did x or y because she is being selfish)

2) even if at one point we are unselfish if we take the wrong actions we can be unselfish "no longer".  It can change.  Just like we can improve we can head back down the ladder again.

Thanks for the maare makom