I live out of my notes, but part of that is due to the format of my notes and how I work, in general.

While learning a new subject (almost always from a big, fat, e-book), I take notes as I skim/scan the material. I'll go from cover to cover about 4-5 times, enhancing my notes each time. I re-read my notes in-between reading the book to see what I don't understand from my notes. These notes, later, become a reference material for me.

When I come across something new idea/technique (new to me, not necessarily "revolutionary", in general), I find the relevant document in my note library and add to it.

About once a year or so, I go through most of my notes and re-organize things. Since I've been doing this for 15-odd years, re-organization is usually moving a small percentage of text around to another file -- my notes repository is very well organized and often I remember exactly where something is that I'm looking for without resorting to searching.

All of my notes are written in Markdown -- something I started doing about 2 years ago. I converted all of the existing notes that I felt were important into this format because it gave me the best of all worlds -- I get solid, pleasant (and configurable) formatting, code highlighting which can be viewed in a styled format in-browser or printed[0] and yet still end up with a plain-text document that plays nicely with git. All of my notes are stored in five different git repositories which are now all stored on Keybase's Encrypted Git. I keep separate repositories to separate out work and personal, but I have a programming-notes repository that's dedicated to generic notes I've taken on the programming languages I write in (each has its own folder with several documents, but minimally a "cheat-sheet" and "snippets" document which should be self-explanatory).

The Markdown bit is key -- I am not always in a GUI, sometimes I'm having to refer to things from the terminal and everywhere I go, I have a copy of that keybase repo. Everywhere I go I also have grep and when I can't remember something specific, but I know I took notes on it, grep finds my answer faster than evernote/onenote's search function ever could and I can read what I need right in the output of that command with an "-A/-B" of sufficient size, or just open the file in VS Code if I want to see it with formatting.

I get where you're at, though. You don't get value from taking notes until you've taken a lot of notes and it takes forming the habit of taking notes to get that value -- not being certain that you'll get any value from your notes because of the tool you chose or the format it's stored in can be a barrier to forming that habit. I started keeping programming notes outside of those I took while learning a language when I realized I was constantly googling the same thing about languages that I didn't use frequently enough to commit those things to memory. That's fine and all until you can't remember the specific incantation of search string that you used, or Google changed the ranking of things for the search term, or the site that had that great nugget of information was reformatted or changed URLs so you can't find it and your bookmarks are no good any longer ... I believe I started taking daily note-taking seriously after spending a day between Google and writing code only to throw most of it away when I finally found that library I had been looking for the next day after remembering the author's name and searching directly for him/her rather than what I thought was the name of the library[1].

[0] I use Markdown Enhanced Preview with Visual Studio Code and have written customer proposals and full-on "report-style" documents. When I had to do the first one of these at the job I took in March, I was given a Word template to work from and after swearing at Word's awful WYSIWYG interface, I went into the CSS editor for Markdown, added some rules and managed to get it to interpret my Markdown in a manner that looked identical to the Word template, complete with a full-page "Title Page", headers, footers, and a formatted Table of Contents that it generated automatically from headers (a feature of the add-on for VS Code). I've sent that CSS file over to at least 20 different coworkers via Slack.

[10] The thing is, I remember neither now, but it was a C++ library that had to do with string edit distance algorithms and I could probably find it given a few minutes with grep targeted at my C++ folder.