Does this surprise anyone? Of course not. He may have that animal cunning, but he's also stupid and lazy. Via NBC News:

WASHINGTON — President Donald Trump has not held a single mock debate session, and has no plans to stage a formal practice round, as he readies for his first faceoff with Joe Biden in less than three weeks, according to multiple people familiar with the discussions.

The president has dismissed the typical debate preparations he participated in four years ago, joking to aides and allies that he’s been preparing for debates since he was born. His ability to fire back at an opponent in real time, he’s argued, “isn’t something you have to practice.”

Instead, Trump has so far chosen to prepare through informal discussions with key allies and with briefings from top officials in his administration on various topics that are likely to come up, these people said.

“It’s not the traditional, ‘we need Chris Christie to fill in and play Hillary Clinton’ like we did four years ago,” one of the president’s allies said, referring to the former New Jersey governor who has helped Trump prepare in the past.