I imagine knitting would be a rich field of study for any psychologist investigating motivation. I'm interested in how individual projects create their own milestones or small goals that keep you knitting.
The blanket I'm knitting from Noro Taiyo is the nth degree in motivated knitting. With colour-changing Noro yarns there's always the 'I'll just knit till the next colour' factor, but this blanket has the added goal of 'I'll just knit till the next corner'. As the blanket gets bigger, the next corner takes longer and longer to reach, but it certainly results in motivated knitting.
I really like the composition and texture of the Taiyo, but as often happens with Noro, I'm very grumpy about the knots and joins in the yarn. It's relatively easy to spit-splice with Noro so the joins themselves are not disastrous - what's problematic is the very disjointed colour jumps at the joins that disrupt the colour sequences. I'm finding myself having to break the yarn in other places to reconstruct colour sequences that are reasonably balanced.
There are other subtler motivations in knitting. I think socks make for a perfectly staged knitting project with lots of intermediate goals: the cuff, the leg, turning the heel, the foot, the toe, (or the reverse for toe-up), and then repeat for the second sock. I'm currently knitting a vintage-style Nancy Bush sock (Gentleman's Sock in Railway Stitch) and it has the added motivation of a six-row repeat pattern - 'I'll just finish another pattern repeat'.
With my rather awkward knitting style this is slow knitting. (I was taught to knit by my father many years ago. He was not a particularly skilled knitter, but he was very patient.) But I'm very happy so far with the outcome, and it doesn't matter if it takes some time. I love the fussily detailed, but ultimately streamlined socks that many vintage patterns produce.