I was hit on the head a lot as a child. My memory isn't great, so I take a LOT of notes. Those notes and the writing/searching tools to use them are very literally a memory prosthetic.
Zettelkasten is a methodology of organizing a LOT of notes.
I index by topic, date and people involved. I can look up a friend and re-read every shared IM, email, and event I logged almost instantly. Faster than any website can. It's my own personal pile of papers future historians will be excited to find because they can actually read it.
One of my biggest frustrations is that most of my note-taking tools are not permitted in my workplace for security reasons. I have to keep all my notes on their infrastructure. I'm going to loose a chunk of my brain when I change jobs someday.