I've done this continually—initially writing in spiral notebooks—since I started writing computer games 40 years ago.

When at Apple, where it is probably widely known that there is an internal bug-tracking system called "Radar", a co-worker called my notebook style "John-dar" since I kept copious one-line to-do lists of issues still to resolve, tasks to tackle, etc. When all the circles next to each entry were filled in we could send the code to QA for integration testing.

To this day I keep a Field Notes book in my (largish) wallet to take notes as I think of things on the go. (Long, boring drives seem to be the best times when these ideas come.) I am in the habit of scanning the Field Notes digitally as they fill up and are replaced. (I only lost one when I lost my whole wallet on a 7-day Katy Trail bike ride. Still stings—why no one contacted me about it since email and phone # were in the Field Notes book.)

Sometimes it is fun to pick through older ideas, see ideas that I actually tackled and completed, other ideas that I am reminded of that may someday see the light of day…