I find Campaign Logger to be a very useful tool.
https://campaign-logger.com/
It has both online and offline versions. Essentially, it allows you to easily tag entries with categorized keywords.
For example, an @ indicates a person, while a # indicates a place. So if I created a short entry like the following:
@"Fanalialae" wrote a post on #"ENWorld".
Fanalialae would show up under the Person category, and ENWorld would show up under Places. I could then click either of those tags to bring up all entries containing those tags.
Admittedly, while it is intended as a DMing tool, I tend to use notebooks and Obsidian Portal primarily when DMing. It would likely be a useful addition to my DM's tools but I'm old, stubborn, and set in my ways.
But it's phenomenal as a player. I have a DM who creates deep, rich, convoluted world's to explore. If you don't pay close attention, you can and will miss things. So nowadays I take handwritten notes during game and then transcribe them into Campaign Logger, tagging anything I think might be relevant. It makes unraveling the mysteries of his world so much easier than working from memory, since I just click a tag and see all entries that contain that tag. It's also nice when my DM asks when the last time was that the party resupplied, and I can give him the exact in-game day.
While you can export the text, it's not entirely ideal as-is because it does leave the tag symbols in. I wrote a program that automatically scrubs them out, so that it's easy to update the Adventure Log in OP when I rewrite my notes.
