Why stash?

Well, I've come to realize that if I have ONE skein/ball/sample of each yarn, when I spin, I can spin to that weight/ply/fiber content and actually get pretty close to what is called for in any given pattern.

The trick, of course, is keeping the labels...

Are other spinners/knitters organized? Do they actually keep notes of what they spin/knit and refer back to their notes?

I know I should do this... especially if I want to reach my goal of making a living selling and spinning yarn.