How is it that Trump can lie so completely?

Today Trump made a public comment about his wall.

President Donald Trump promised Wednesday that a “big” and “strong” border wall is “very, very on its way,” even as Congress moved toward considering a Homeland Security spending bill that would provide for the construction of about 55 miles of new steel fencing.

“As we review the new proposal from Congress, I can promise you this: I will never waver from my sacred duty to defend this nation and its people,” Trump said in a speech to a conference of city and county sheriffs in Washington.

“It’s a wall that people aren’t going through very easy. You’d have to be in extremely good shape to get over this one. They would be able to climb Mt. Everest a lot easier, I think,” he said.

Every single word of that is a lie.  A really, really big lie.  Yet, Trump just rolls out these lies without even thinking about it.  Trump lies as readily as the rest of us take a breath.