Comment by schoen
11 years ago
When I was a kid, the kid down the street and I started digging a hole in his backyard. We wanted it to become a tunnel network.
The hole got deep enough for both of us to fit inside, but somehow it became much more difficult to continue digging at that point. Maybe, as the article suggests, we hit a rock, or maybe it was the exertion of lifting shovels full of dirt above our heads.
To me digging always gets less fun as soon as moving material out of the hole becomes the primary obstacle, rather than breaking new soil.
Same reason why pickaxes are more fun than shovels. All breaking soil, no earthmoving.