my hypothesis about fermi's paradox...  we all know that we are not the only intelligent species in the universe, but why has no other intelligent species ever made contact with us? well, i have a hypothesis for this.  
    
what if some intelligent alien species observes our wars, racisms and bad things in general, making them realize that it was not worth joining forces, sharing technology and etc?   
I don't believe in conspiracy theories, this is just a hypothesis I had while I was in the shower.