When it gets cool outside, my hands get itchy for a crochet hook.  It is a skill my mother taught me when I was very young, and all she knew was how to go back and forth with only one kind of stitch.  I experimented with this motion when I was a child, and even then was able to get some moderate variations.  I still do this now.  I think, ' Hmm, how do I make that?', and I just start making something.  Sometimes I count a few stitches (only if I find I absolutely have to, though).  Sometimes it doesn't work out, but most times it does.  The thing is, it really doesn't matter, because I just like to crochet, and if I keep crocheting, then I end up with too many things, so you see, then I have to sell them, so I can make more things.  It's all about the making, really.  And the yarn.  You Yarnies out there know what I'm talking about. 
Not to mention, it's something like a science experiment, making something really big with wool yarn, and seeing how much it shrinks in the washer.  Oooh, and I like to add the variation, 'how long until I remember I am felting something in the washing machine'.  It's usually about when the machine has stopped.  That's not when you are supposed to remember.  The people who are good at paying attention to one thing at a time, will actually stay in the same room  while their pieces are felting!  Amazing.  I keep trying.