We were boring him
After a couple of minutes, he decided he had enough and ambled away.
On the trip we used two Land Rovers. We would travel around the parks independently, staying in radio contact should something exciting happen. While our elephant chose to keep a gentlemanly distance, an elephant came up within a couple of feet of the other truck. That might have been a little *too* close for me.
A little later in the trip, once we were in the Serengeti and elephants were much rarer than in Tarangire, Charles told us about how an elephant earlier this year had become annoyed with one of the trucks, impaled it with his tusks and flipped it over. Charles always told us these stories after we had left the area where they were most likely to be replayed. Smart man.