Because I've knit them a fence.
Progress between Tuesday night and today doesn't appear quite so rapid due to that fact that I'm working on many more stitches but I'm nearly ready to divide for the arms. Even if my pattern (with modifications) didn't tell me that this is the point to do so I'd have a pretty good idea from the fact that knitting all the yoke stitches is now really awkward. Maybe it could be a new rule of thumb that you should divide for the arms when the whole yoke becomes a pain in the arse to knit, like Elizabeth Zimmerman's maxim that the ribbing at the top of a sock is long enough at the point when you get bored of it.
I also had one small set-back last night when I had to rip back two rows of the fence after realising that it looked more of a size for keeping in the exhibits at Jurassic Park rather than a field of sheep. I'm still not completely sure about the fence but I suspect that everything will look great as soon as the sheep have their little black faces. So sweet.
I'm really pleased with the back of the work. I've followed Kate's example and not tried to weave in any of my floats - even the super long ones - and I think my tension is much better as a result. The only place where the floats aren't quite long enough is behind the sheep but hopefully this will just make them stand out a bit more from the body of the jumper. Although I got through the stranded portion quite quickly it has made me realise that I need a technique for stranded knitting (other than dropping the yarn every time Ichange colours), especcialy when purling. Luckily I'll have plenty of leftovers from this projects for some colourwork practice.