Yesterday I dyed yarn. Most of the yarn was freshly dyed, but some of it was me changing or "fixing" yarn by overdyeing what I dyed the other day. All sorts of things can happen when you dye yarn - sometimes a brand new jar of dye comes out looking so very different than the last one.
Or a color looks completely different on a different fiber blend.
Or you get splotches of a color you don't want. I don't like when that happens. I like things to be predictable, for the most part.
I feel like I should always be able to do everything perfectly the first time I try. Yarn dyeing helps me remember how silly a burden that is to place on yourself, and that sometimes a do-over can turn out even better than the original plan.