My lord, the master of the west wind

Arriving home from faraway travels, after many month's absence and a grueling long trip, how pleasant it is to be welcomed at one's threshold by an old faithful friend who'd rushed on ahead to sweep the cobwebs, warm and light the house and whisk up a frothy tea.

We sit and chat and then in passing she mentions the west wind:

In the ninth month, the west wind quickens
Under the cold moon, flowers of frost have formed.
When I think upon my lord, the spring day seems long.
My soul, nine times, rises towards him in one night.

In the second month the east wind comes
Tearing at the plants till the flowers lay bare their hearts.
When I think upon my lord, the spring day passes slowly.
My heart, nine times, leaps up to him in one night.

Which is a fancy way to say that I have found, upon arriving home, a copy of The Pillow Book waiting in the mailbox -- of all the books that I had preordered, this one was the first to come and the only one to be already waiting. So, having dropped my bags and shoes at the door, I curled up on the sofa with it. This poem, by Po Chu Yi, is mentioned in its 150th chapter (as Morris numbers them), but only obliquely, of course, with the sort of reference you are liable (and calculated) to miss.

I can't explain what I find so very moving about it... surely, I hope, not just the fact that I do not understand it (and my head spins trying to understand it).