I have read several biographies of him, and visited his museum and homestead at Plymouth Notch in Vermont, which is a great place to visit.
It was, even up to the time when Calvin Coolidge was sworn in as President in 1923 by a kerosene lamp in Plymouth Notch when Warren Harding died, a place that still lived in the past.
One of the things about Calvin Coolidge that I greatly admire, is that he went his own way. He did not seem to care one whit about what people thought of his manner of speech or appearance. When he was President and would visit Plymouth Notch, he took part in the traditional farm chores. And in doing this, he would don the traditional garb that he had used his entire life working on the farm, as shown below:
His advisors were horrified that he would be shown in a way that made him look like a backwards hick, but Coolidge did not care since that had been how he had spent much of his life, and the photographers were always trying to get a picture of him like that.
And it wasn't about show, about getting the press involved for political purposes. It was about the farming and the work, which even as President, he felt compelled to (and wanted to) help out in. But what I admire about him by far, and it is not even close, is the famous anecdote about a dinner party he attended as President where he was seated next to a socialite who was determined to drag the notoriously close-mouthed President into a conversation:
WEALTHY SOCIALITE: Good evening, Mr President! My husband told me I wouldn't be able to get three words out of you during the entire dinner! What do you say to that?
PRESIDENT COOLIDGE: You lose.
That says volumes about who Calvin Coolidge was. He was extremely intelligent and driven, and had a healthy sense of humor, but...he didn't believe in using his speech as a way to ingratiate or elevate himself.
Biden can't speak intelligently, and for good or bad, Trump cannot bite his tongue (appropriate for THESE times we live in!) but Coolidge, well, they didn't call him "Silent Cal" for nothing.
Can you imagine: a politician who didn't want to speak, and especially, not to speak about himself? The Horror!