Once attained, even if by accident or trial and error, most knowledge is
retained for life, thanks to the cat’s excellent memory. Even hunting
techniques buried under years of neglect in the well-fed house cat’s
brain will be recalled with ease should the feline, for some reason,
ever have to fend for itself.

Easily frightened, a cat will
retain very strong memories of any incident that it considers
threatening. All it takes is one face-to-face encounter with a growling
dog to convince a feline that the entire canine species is best avoided
forever. However, positive experiences are just as easily stored and
recalled, particularly if they have to do with food or play.

As
any cat owner knows, domestic felines respond well to familiar sounds,
such as can openers, the rattling of their dry-food bags or the crinkly
noise of a favorite toy. Many of them also have an uncanny ability to
know the hour of their regular breakfast time, waking up their owner if
he or she tries to sleep in. Source: AnimalPlanet