I did not take notes when beginning brewing. The effort required to quickly flip back and forth between sections in How to Brew to make sure I’m not missing anything, while trying to judge my mash temperature, and nursing a sick propane burner back to health was just too much, and to add note taking to that? No way. Heck, if it wasn’t on a Brewer’s Friend checklist, I’m certain I missed it.
After spending some time in the trial and error stages of all grain brewing, I finally got serious about taking notes. I think it is the only true way to grow as a brewer, home or professional. I can look back a few brews and see how much water I am using, or what the pH was on a particular mash, all of which would be practically impossible without notes, be they handwritten or in a piece of software.