again, not something people do wrong but just another fun trivia chapter
so, if you look well into small parts of TVD (and like one scene from TO) there are different versions of a diary in place. Since the show is called 'The Vampire Diaries' i guess it would be fun to sorta place it in various seasons
so they find ways to incorporate any form of documentation on the show, and most of the time it's really subtle
Elena and Stefan obviously are those angsty people that write down their feelings in journals (not so subtle, that one's shoved into your face the majority of the first season)
The entire line Gilbert Journals that were a huge deal in S1.
I'm pretty sure when Alaric first showed up he wrote about killing his first vampire and we heard it through voice-over.
when Tyler was first transforming he found a bunch of Mason's stuff and saw that 'he chronicled everything' he found a notebook where Mason wrote about the wolf transformations. As you may know, 'chronicles' is a synonym for diary or journal.
Whilst trying to find a way to kill Klaus, Mason's ghost led Damon to the underground tunnels of the Lockwood estate and pretty soon Elena and Alaric found the wall littered with ancient viking symbols and the story of how the Originals came to be. Damon referred to it as: The Lockwood Diaries: Pictionary Style (though technically this would be the Mikaelson Diaries)
Even Katherine started writing in a diary when she was human, though it clearly wasn't the therapy she wanted.
then you've got Damon making a video diary in the 1996 Prison World
Pretty soon after he escapes, Bonnie takes it and starts documenting her own escape out of there
When Elena went to sleep she made everyone promise to write in a diary so she could read about everyone's adventures and experiences whilst she was comatose. So during S7 and S8 we got a lot of voice-overs from Caroline, Bonnie, Matt, etc.
in The Originals around season 1, Hayley finds Elijah's old journal and reads it, leading to finding where a witch (turned bad guy) was buried
in a way, Klaus' art pieces are memories to him
even in Legacies, Landon keeps a journal
if i missed any, please be sure to let me know and i'll add it :)