I don't write down anything and I start all my projects from scratch. I've never found a need to take notes, etc....If I ever want to see what I did on a certain project, I just open that project and take a look.
That might work with DAWs...but not so much when tracking to tape and mixing OTB, which is where my note-taking SOP stems from.
But even with DAWs...you really can't "see" which mic you used, where it was positioned, how you set up a particular instrument or which instrument it was...unless you also write all that down somewhere in the DAW.
I have a bunch of guitars...I'm never going to remember which guitar I used on each specific track unless I write it down...either with DAWs or analog recording.
Is it absolutely important...?...naaaaa...but I think it helps to have some sort of "archive" of what you did, and somehow paper just seems to outlast computer data!
For each song I do...I have a lyric sheet, a chord structure sheet, a tracking sheet and finally a mixing sheet. I also write other things down along the margins, like which reel of tape it's on and starting SMPTE point, the BPM of the song and anything else I think I would want to remember.
I still have my notes from the late 70s when I was using a 4-track...!...

...and I have gone to them a few times to check on what I did for a particular song or sound.
It's just a studio SOP...and we all have our own that works for us.