Once upon a time, Stefan hadn't been the only Salvatore to keep a daily journal. Giuseppe had once said in passing, "A daily recounting of one's activities is a good way to build one's mental faculties, and to keep for posterity the actions of a great man." Once upon a time, a passing recommendation by Giuseppe Salvatore was all it had taken for both of his sons to jump into action.
It had taken Damon until 1943 to realize that he neither needed the journal's help to aid in building his mental faculties, nor in making him a great man.
He would never be a great man. The first requisite of such was to be a man. Damon had long since been a monster, in both name and deed.
He took his journals, which he had long since taken to carting around in a decorated wooden chest, and found for them the perfect hiding place: far away from anywhere he had ever loved, and in a place he was unlikely to ever return. He bid farewell to them as he would any great love or friend (or brother): with a deep breath and the self-assurance that he was in the right (and the ability to keep at bay any contentious thoughts).
When he locked away his journals (and he did lock them away, where they hid, many times over), Damon made one final decision. His journals contained his life, his thoughts, and his hopes. They contained what every good philosopher dubbed the essence of humanity. When Damon walked away from those journals, he told himself he was walking away from the last of his humanity, shedding it like an old, dead skin.
He knew that it would take something close to God's own will to shove those journals back in his face, and then, and only then, would he let himself be the man who had been willing to write in them. To have those hopes and dreams, and to begin such tasks at mere mentions from those he loved and admired. To have such love and admiration.
Only Stefan even knew the journals existed, and Stefan had long since shed his own humanity. A very good detective might question the bank account Damon held upon which only one withdrawal was ever made, but what detective would ever check? Who would ever become close enough to try?
Humanity led to closeness, and Damon was walking away from his own.
In 1943, amidst the destruction of the Second World War, Damon left the remnants of his humanity with a box in the most beautiful place he had ever seen, and walked away.