Relevant story.
A very long time ago I had a girlfriend whose family had a blue heeler (and yes they lived in the Queensland outback). The dog’s favourite game was the “ball over the fence” game. To play the game, you took an old tennis ball and tennis racquet and went outside their side boundary fence. The dog would follow you. You hit the ball over the fence into their back yard, which was quite large. The dog would tear off at full speed about 20 yards or so to the front gate, 20 yards or so back into their back yard, and then find the ball, then run 20 yards to the front gate, 20 yards back to you, and drop the ball.
My girlfriend’s family were bored of the “ball over the fence” game and so the dog had some difficulty persuading the family to play but because I was new to the game, I was more willing - which the dog quickly learned, so whenever I was there it was:
Dog: [drops ball at my feet] WE PLAY?
Me: OK but I’m having lunch now, wait a bit
[three seconds later]
Dog: [picks up ball and drops at my feet again] WE PLAY?
Me: Hold on, hold on, still eating
Dog: [picks up ball and drops at my feet again] WE PLAY?
and so on. Till I eventually went and played the “ball over the fence” game for a while. After which I had approximately zero seconds break before:
Dog: [drops ball at my feet] WE PLAY?
Me: OK but we just finished, wait half an hour
[three seconds later]
Dog: [picks up ball and drops at my feet again] WE PLAY?
Me: Hold on, hold on
Dog: [picks up ball and drops at my feet again] WE PLAY?
The family wisdom was that the dog simply never got bored of the game and would play until the end of time, as long as someone was willing to keep hitting the ball over the fence.
I was staying with the girlfriend’s family one weekend. It was in the low 40’s Celsius (around 110 F) and I decided to test the family wisdom by just continuing to play the game until either the dog or I melted. Needless to say all I had to do was stand on the spot (in the shade of a tree) and hit a ball with a tennis racquet occasionally while the dog had to scream around in the extreme heat, so I undoubtedly had the easier task.
I’d say the dog lasted maybe 45 minutes to an hour before it finally collapsed exhausted under the shady tree, giving me a slightly sheepish look, as if it was letting me down by giving up so easily (!). But it was probably only half an hour later before:
Dog: [drops ball at my feet] WE PLAY?
I was tempted to repeat the experiment but my girlfriend told me I was being mean by “requiring” the dog to keep running around in the heat - and she was probably right although it was the dog that wanted to keep playing, not me!