> The first reason for this is that forgetting is a filter. When something you read resonates with you sufficiently for you to recall it without effort, that means something; it means it connects with your ideas and experiences in some relevant way.<p>I take an issue with this assumption. When I leaf through my past notes, highlights—hell, even stuff I have written myself—I am surprised at many relevant things that I completely forgot about. It's true forgetting is a filter, but one mustn't underestimate the brain's capacity to forget useful stuff too. Maybe it's something you didn't need in a while, and need it now. Maybe it has become more relevant than it was in the past. For eg, I have restarted journaling recently, and this highlight from "On Writing Well", immediately hit me:<p>> “Go to your desk on Monday morning and write about some event that’s still vivid in your memory,” he says. “It doesn’t have to be long—three pages, five pages—but it should have a beginning and an end. Put that episode in a folder and get on with your life. On Tuesday morning, do the same thing. … Take whatever memory comes calling; your subconscious mind, having been put to work, will start delivering your past.<p>It's written for a different context, but it made me realize a different way to approach my journaling.<p>However, I agree wanting to retain everything is needlessly ambitious, and counter-productive. I was once obsessed with making notes about everything I read, but soon, I realized how unenjoyable it was making my reading. The better approach, I found, is to just make highlights. And go over them once in a while (a few months or so). That's enough of a knowledge-retention system for me.