I keep logs and records for some beers, not for others. If I'm experimenting and I have high expectations, I keep a log. If I'm experimenting but I have a general idea what I'm doing and it isn't anything other than a daily "evening beer", I don't keep a log. I have a pretty good idea what is going on.
I have a few brews that are works in progress. A great beer that is loved by me and my friends and family of which I'll make minor changes each batch. I keep very careful notes on these. Not just normal notes, but tasting differences vs. previous batches and so forth.
Some people brew like jazz, always improvising and allowing the moment to dictate the result. Some people brew like an orchestra, every note predefined and meant to be followed exactly. Some people brew like me (a retired rockstar); sometimes high, sometimes low, a little exact, a little lost, anyway the wind blows....nothing really matters to me:rockin: