I've actually come right out and asked mine how he could sleep. He will lie about anything and everything to protect his drinking. It doesn't matter how absurd the lie is. I've finally stopped walking on eggshells and will now call him on it when he's lying.
He also does not take responsibility for anything he does. There is always some reason why he did what he did. I call it the "whatever excuse works" defense.
I believe mine might be beginning to see the pain that he is causing not only me but himself and his family as well. I think the pain he causes matters to him and he doesn't want to hurt us but again - anything to protect the drinking.
We had a conversation last week when he was sober where he finally admitted that he knows what he is doing when he hurts me (both intentionally and unintentionally) but he can't stand to face it so he will not acknowledge it and instead defend himself with whatever excuse is handy.
It really hurts but I have to keep reminding myself that it is not personal - he would do it to whoever was here. It's truly nothing against me. It took me a long time to accept that though. Once I did accept it though things were easier for me.