I'd have a hard time with a physical notebook. Speed and search are key.

My workspace is just a markdown file, with dates and work-in-progress (scripts, bug investigations, design notes, task lists...), by date (reversed), rolled up to month files. If something (non-code) bears remembering, it's normalized and published to others, or put into my own topic space (leaving the WIP notes).

The key feature is global search over all such files. I can find any activity and any topic in seconds, with a search-bar overview of all places where I addressed some subject. (As a result I tend to create unique names.)

As a discipline, speaking directly and constantly to future self does help establish more methodical approaches, reinforces context awareness (and avoid ratholes); I restart even small projects where I left off, and scale the number of projects I try. Somehow the act of writing provides a reflective time/instant boundary (think: clocks in a functional universe) that orients the work in time/relevance to avoid wasting time on things that matter less.