(Source unknown and many years old)
From 13 to 18 a woman is like Africa - virgin and unexplored
From 19 to 35 she is like Asia - hot and exotic
From 36 to 45 she is like America - fully explored and free with her resources
From 46 to 55 she is like Europe - exhausted, but still has points of interest
From 56 on she is like Australia - everyone knows it's down there but no one gives a damn.