What he was writing in his diary:
Dear diary, Mithrandir visited me today and he was unbelievably annoying, a hypocritical whiner, self-righteous, arrogant to the max and incredibly disrespectful of the humble office of Steward, supercilious, subtiley advancing the perfidious plots of that smiling villain Aragorn, (Do I need to remind you of the way he slithered into my father's heart?), a liar, proverb peddler, cheesy moral-monger, and as a new form of villainy he brought a Halfling to spy on me! Peregrin Took has been peregrinating long enough with that devil who now calls himself Gandalf the White. I have to leave now because that Halfing is about.
Your longsuffering Steward,
Denethor