For a lie to gain real power, it must continue its existence separate from its creator. If it can be repeated by others, retold in a variety of contexts, it has undeniable influence. If it can separate itself from its birth, a lie has real control.
I suppose it's the ultimate goal for career liars - to create a self-perpetuating fiction. But it scares me to think of something I've invented living on without my guidance. I suppose that's why I lack any real desire to lie for a living.