I read an article yesterday and it suggested that was because George W Bush impressed upon him the importance of having a plan and sticking to it after Bush was surprised at the end of his term with all the people coming out of the woodwork to ask for pardons, so it was on his mind when they met before inauguration. It was an ok article, CNN: https://www.cnn.com/2021/01/18/politics/donald-trump-elevent...