I blatantly stole this clever title from my friend and collegue Bill Shaw and his post of the same name -- the most popular post the Summa Blog has ever seen. The point of his post was to take notes. Even small, simple notes can save a lot of time, confusion, and pain in the future.
So as you can guess, not enough people take notes about software. But I find that fewer people take notes about improv. In classes, in rehearsals, when getting notes.
In my experience, though, the same reasoning applies. I take a lot of notes. Workshops and classes are the easiest example. I write down insights I learn, exercises I find valuable, and quotes that stick with me.
All of this goes into Evernote. Taking notes help you to remember, but you will remember even more if you review. Before a level, I will review notes from the previous level. Before a rehearsal, I try to review my notes from the previous rehearsal. And I review workshop notes whenever I struggle with that topic in my own work.
My system may not work for you, but I do hope you find your own. Without notes, we are all floating in a sea of learning as temporary as the scenes we perform. And it becomes that much harder to learn from our mistakes.