Frankly, I doubt that an explanation is called for. One doesn't have to be able to successfully count in 5/4 to enjoy listening to Take Five, or at least to appreciate it. What's more, what might once have been out of the ordinary and even odd hardly raises an eyebrow today. Listeners today may not even notice that the piece is in an "uncommon" time signature. Still, if anyone wants to delve into the subject, Wikipedia has an extensive page on Quintuple meter, and considerably more on time signatures in general.