It takes time.

Yesterday, either just before or while we were driving to the airport, we wondered about what dogs' senses of time are like.  "He'll probably have two weeks of being really unhappy," one of my friends suggested, "and then he may just be fine."   

Today was the beginning of the two weeks.  I fear that I alone am a somewhat less interesting presence than his two excellent parents.  He continues to look out the window, or to lie beside the door through which they always come when they return from the airport.  I continue to tell him that they'll be back later.  With luck, the heat will have broken by the morning, and we'll be able to take longer, more distracting walks.