Hypothesis: Non-Habitual Movement Wakes the Brain
Differentiation works because it is, almost by definition, non-habitual — and non-habitual movement wakes the brain from its bored slumber.
Your organismic system is exquisitely tuned to notice change, and equally good at tuning out the familiar. Habitual movement patterns become invisible to your own awareness — your system has decided they don't need monitoring anymore.
Non-habitual movement interrupts that efficiency. It forces the organismic system to pay attention. This is why Feldenkrais lessons spend so much time in variations, reversals, unusual sequences, and unexpected combinations. The point isn't the variation itself — it's the waking up that the variation produces.
Think of it as seduction rather than instruction. You can't tell a sleeping brain to wake up and attend. But you can offer it something genuinely strange, and it will open its eyes.