That's a very valid point. I used to call writing in Evernote, writing into the void.
Though the beauty of any system is you design it. You get some kind of say in what's important. I trust that more than randomly depending on your brain. The brain can be a weird place. I have embarrassing memories from my childhood, I don't know if it serves me anymore, but they're there.
Also, I get distracted too easily, having a list of tasks I'm working on keeps me on track.