For the last couple of months Robert, the owner of the other brown Labrador, pops by the office around lunch time so that Tag and Sam can play in the meadow.

Let me paint you a picture:
Tag awakens from REM sleep with a start and sits straight up looking directly at me. Eventually I too hear the clop, clop, clop, clop of someone walking. He runs to the window and sits perfectly still. Stiller than he does for a treat. I mean STILL. When the mystery person appears, and Tag sees that it's not Robert with Sam, he walks back to his pillow, whimpers, and sighs. This goes on for hours!

It's like the chapter Pavlov's dogs and Conditioning from Pysch 101 unfolding before my eyes.