A Mexican woodpecker and a Canadian woodpecker were in Mexico arguing
about which place had the toughest trees. The Mexican woodpecker claimed
Mexico had a tree that no woodpecker could peck.

The Canadian woodpecker accepted his challenge and promptly pecked a
hole in the tree with no problem. The Mexican woodpecker was amazed.

The Canadian woodpecker then challenged the Mexican woodpecker to peck
a tree in Canada that was absolutely 'impeckable' (a term frequently used by
woodpeckers). The Mexican woodpecker expressed confidence that he could
do it and accepted the challenge.

The two flew to Canada where the Mexican woodpecker successfully pecked
the so-called 'impeckable' tree almost without breaking a sweat.

Both woodpeckers were now terribly confused. How is it that the Canadian
woodpecker was able to peck the Mexican tree, and the Mexican
woodpecker was able to peck the Canadian tree, yet neither was able to
peck the tree in their own country?

After much woodpecker pondering, they both came to the same conclusion:

Apparently, your pecker gets harder when you're away from home.