You can sing the lyrics of the Pokemon theme song to the tune of Amazing Grace, and still have the correct number of syllables in each line, so it won't sound awkward. Go ahead,
try it. (Of course, this also means that it works the other way around, too.)
On a completely different note:
Over the course of human evolution, babies' heads have gotten bigger over time, while females' waists have gotten smaller. This is one of the reasons why childbirth is so horrifyingly painful. :,D
Similarly, human babies are technically born prematurely. Nine months is really not long enough -- but it's the longest amount of time that the average mother's body can tolerate. So, ready or not, out ya go. This is one of the reasons why human infants are so completely dependent on their mothers for the first few years of life, despite the fact that many other mammals give birth to young who can walk within their first few
days of life, and even the offspring of most primates are relatively far ahead in development compared to a human newborn. (
@Dervish :P)