I used to write down all sorts of random little bits of info like that when I was a kid too, it's interesting how I never thought of the concept again until I saw someone be like "so this is a thing." It's never to late to try it out though, I suppose!

I'm not an artsy person at all, so I'd be going for mostly text and stickers/washi/clippings for any decoration. The Leuchtturm does seem popular, I'll definitely bookmark it for consideration.