A flimsy sheath, a false illusion

I was realizing how little substance there is to a man.  I am just my actions.  I have no constancy, except where I decide to have.  I could be anything...but I choose to view the world and act towards the world as this creature me.  I don't have any true attributes or nature.  I'm just a creation.  I could be evil and carnal in the next instant and it wouldn't be out of my nature.  It would just be a change.  You could say a change of 'character', but if I can so easily change....can you really call it that?  I don't think any man is a true constant.  Anyone could be a piece of crap the next moment.  What's stopping them!?  Why not just fail!?  What god-damn point is there to continue on in honor and virtue and class when you could just as easily let it go and still be the same person.  Everyone's so fake.  Even if that fakeness is good.  Just an illusion that you manipulate from day to day until the day you die and that illusion falls off and you become a true sight to all.  A mound of flesh.

Ugh.  Why is life so depressing somedays...Brain chemicals....random balances determine who we are.  We are nothing but a result of some mechanical operation in biology.  Life is a fail.

I know all of this ranting is just bull****; but I can't help but feel it's true at times.