I spent a day enjoying the stiffness from the exertion of moving so much sand around. Then, I was done. Yesterday, as I was in the Head-to-the-Knee pose (the pic is from the Yoga with Ateeka - Asanas website-- it shows the the style of Asanas I perform) I suddenly understood the stiffness was part of my story about the effort... and I let go my attachment to the stiffness.
I recall with great fondness words my yoga master said years ago. One of his oft-repeated sentences is "If you strain, you are doing it wrong." Was he speaking of just postures? I have come to understand this applies in all aspects of my life. I'm attached to having pain and stiffness (I earned it, darnit!), and so, I get to have pain and stiffness. I strain to let it go, when in truth all I must do is... to let it go.