Millennia old codices are extremely rare, and they've survived either by dumb luck or because they were treasured.
Maybe OP is a famed thinker, whose disciples will carefully preserve their notes; or their house is in a cave that will be at sealed in a landslide; or they will die in a peat bog clutching their notes to their pallid breast as the life force seeps from their body, submerging them in preserving ooze...
99% of an individual's life experiences are lost when they pass. 99.99% of what's left moves from distinct memory to amalgamated collective experience within a generation.
Even for those of us who are blessed with loving friends and family, nearly everything will fade away. The adolescent me harbored mild delusions that history might care about my notes. The mature me is no longer burdened by those expectations, and my notes are better for only having a single audience.