Nearly half of all households in South Korean capital now consist of one person, and there's a reason for that "You become an adult only after you've put your hair in a topknot," a traditional Korean saying goes, referring to the premodern custom of a man putting his hair in a topknot for a wedding ceremony. Conventional wisdom that had dominated Korean society of yesteryear was that one truly comes of age only after committing oneself to marriage. That notion is quickly changing, however, with