The office of the presidency is known for wearing down the mere mortals who hold it.
At the very least, it prematurely ages its occupants. Often, it humiliates them, forcing them to rehabilitate their reputations later (George H.W. Bush and Jimmy Carter). In the worst case, it chews them up and spits them out (Lyndon Johnson and Richard Nixon).
It is a journalistic trope that this is happening to Donald Trump before our eyes. The media constantly write stories about how the president is panicked and cornered, barely able to handle his duties, as the walls perpetually "close in.