I have a habit of hanging skeins of a handy arm of a chair or something rather than winding them into balls before using them. Most of the time this works out, but occasionally it is not a timesaver as the yarn gets tangled and then I have to untangle it and make a ball. Or sometimes a skein just seems to be tangled. I have one that I decided to wind into a ball before I started using it and so far I have spent about 6 hours doing this - I might be halfway through; I'm certainly not any further. Having to untangle yarn can be so very, very annoying!
But just sometimes, I can sit with the tangle in my lap, untwisting, threading through here and there, following the strands to work out where they go and slowly, slowly reducing the mess and creating a gradually growing ball, and find it incredibly soothing.