Lying can be a impulsive defensive reaction to trauma. When accosted or even prompted, a survivor wants to placate the person asking in the best possible way, a perfect way. Reasoning is not included in this reaction, it is impulsive. The survivor needed to have a perfect reality, so he created one. As he gets older, that reality is supported by and bolstered with additional embellishments, the boy/ball/window/ turns into man/friends/drinking, and neither can be told or he will be abused, so he resorts to a version of the truth, or even the complete opposite. The part of the personality that creates that reality is different from that part that defends him, thus the inconsistency.
He cannot stop because he is told to, he needs to find relief for his composite personality maturing, then he will realize he does not need to create this alternate world and will come to feel that this world is not the one he wants, but he wants the real life.
Yes, I have had this problem, yes I have overcome it. I went through being fierce for the truth of a matter, now the process is about letting go, letting those around me be themselves, I can discern the truth of a matter without feeling injustice or unfairness.