I don't know why they lie so much.  But I know that I am always trying to figure out what was a truth and what was a lie.  Like when they express their feelings to you.  Mine said he always liked me and in fact likes me too much.  Then a few weeks later said he has no feelings for me none at all.  What was truthful???  There are lots of things that I am questioning that he said and trying to see if any of it was truthful.  It makes it hard for you to trust again.  Heartbrokengp91