In the 1970s, a young John Danaher was attending a high school in rural New Zealand. One day, an “enthusiastic amateur” stuntman dropped by to perform a series of stunts for the kids. The children watched in amazement as the Australian “daredevil” set his gloved hand on fire, caught a boomerang and walked across a plank he put up between the two buildings of the school. “How can he do that?” the children wondered.

After this final trick, the stuntman took the plank and put it on the ground, letting the children cross it one by one. It was easy for the kids. Then the stuntman looked at them and said something John never forgot: “The plank is the same. I put it up higher and so it took your breath away. But you guys just ran across the plank. The plank didn’t change, your perceptions of it did.