In youth, it was a way I had, To do my best to please. And change, with every passing lad To suit his theories. But now I know the things I know And do the things I do, And if you do not like me so, To hell, my love, with you.
Of course, the liar often imagines that he does no harm as long as his lies go undetected. But the one lied to almost never shares this view. The moment we consider our dishonesty from the point of view of those we lie to, we recognize that we would feel betrayed if the roles were reversed.
You might even ask me to apply my 'theory' to myself and explain what damage I had suffered a long way back and what its consequences might be: for instance, how it might affect my reliability and truthfulness. I'm not sure I could answer this, to be honest.