Read the whole page, i cant put it all in. but there is some truth in it. You have to go onot next page to get full explantion.

Women and elephants never forget an injury. Or so it goes according to H.H. Munro's brief narrative, "Reginald on Besetting Sins." We'll set aside the questionable implications of the first half of that assertion for now. But regarding the elephants, the British author was onto something.



Elephant Memory
Scientists haven't been able to measure elephants' intelligence precisely. Nevertheless, for decades, experts have observed the pachyderms' behavior and concluded that they rank among the smartest in the animal kingdom. That said, the theory of elephants never forgetting is an exaggeration, but doesn't stray terribly far from the truth.
http://animals.howstuffworks.com/mammals/elephant-memory1.htm