At village carnivals a hundred years ago, a common attraction was the
``circus'' of trained fleas. The great mystery was how these insects could
perform without jumping out of their flat box.
The human ringmaster's secret was that, when the show wasn't being performed, a
pane of glass was inserted, creating a ceiling lower than the sides of the box.
By bumping up against this invisible ceiling, the fleas learned the maximum
height for their jumps, and that's what made the show possible.
People, by the power of their expectations, can also restrict performance. For
a number of years, it was accepted that a human could run only so fast and that
the present day track stars had achieved the maximum performance level. The
``four-minute mile'' was a mark that seemed impossible to attain. When Roger
Bannister finally broke this barrier in the 1950s, the feat was repeated
forty-six times within the next four years.
When we think we can, we can. When we think we can't, we can't. Expectations
are very powerful regulators of your performance and abilities.
