It’s not a zero-sum game. If I don’t write it down, I know I won’t remember most of the ideas. And if I do remember it, I will probably not remember it well enough to find it again.
So either I remember 5% of the things I genuinely find interesting, or I can look it up later with just a few quotes or with the author. Additionally, it makes it much easier to reflect. And it’s properly cloud-synced so I’m not worried about it going anywhere.