An RPG like Morrowind, except instead of quests getting logged in your journal, you just get a blank journal. You can make notes, and even draw pictures in it. The text is searchable.

Sharing journals would be a thing. There'd be people who would just make utilitarian notes purely to keep track of the quest objectives. Others might treat it like a diary, writing in character. You'd have some pretty decent boatmurdered style journals I expect.