np++ is still my go to for ad hoc note taking. there are a million beautiful apps for this purpose, but nothing beats the fast startup of np++. Plus you can rename tabs without saving them and just keep them indefinitely. For some reason, no other app lets you do this, they all require saving the file.
I do this all the time. I pull up an editor, take notes on something I'm doing because I can't always fit it all in my mind I don't need to save the note cause, it was just a temporary place to store data/info/thoughts.
Maybe packrats of the mind? Really requires an extremely good search engine for all that. I find that storing everything doesn't work for me because, ultimately, I have trouble finding it again.