Yesterday on a ride in the remote hills, I passed a home up on a slope with a fence running around the property. Inside the fence, just above my head level, were two dogs, one very old who's bark sounded more like coughing, and a young terrier with more energy than all the power plants in the world combined. At first sight of me pedaling along, the young one took off in a cloud of dust along the length of the fence until he could run no further, some 200 feet in length. The look on his face when I reached the far corner just floored me. I felt so bad for him having run out of space to run. So I wheeled back around and headed in the opposite direction so he could run that way. So for the next 10 minutes I had him running back and forth. His thing was he'd wait until I made a move in either direction, then take off at full speed regardless if I followed or not. I even began a verbal countdown before making a move - "You ready? Aaaand GO!" Off he'd run for 200 feet to the far corner. At first he'd wait, believing I was actually heading that way. A couple of hand claps later and he'd come flying back the other way. Because he was above me, before I could see him I'd hear his fierce galloping and collar ID jingling. So funny!