Sparta should be another word for extreme. Legends were build around them and their name permeates language to signify extreme. From Spartacus to Spartan living, from their participation in Trojan War to the latest Hollywood epic 300: Rise of an Empire and the craze in following workout 300. Their name inspires epic performance in the extremes.
Spartans did not do anything half-hearted. There are stories on it was founded by Lacedaemon, a son of Zeus, how they bathed their babies in wine to make them tougher and how they scorned luxury.
From historical perspective, you may find flaws in the stories and their role in War of Empires. But their impact on human behavior, warrior mentality and epic performance is undebatable.