Six of my nieces will head off to college over the next several years. Some have been Facebooking since middle school. Even as they leave home, then, they will hang onto that “home” button. That’s hard for me to imagine. As a survivor of the postage-stamp era, college was my big chance to doff the roles in my family and community that I had outgrown, to reinvent myself, to get busy with the embarrassing, exciting, muddy, wonderful work of creating an adult identity. Can you really do that with your 450 closest friends watching, all tweeting to affirm ad nauseam your present self? The cultural icons of my girlhood were Mary Richards of “The Mary Tyler Moore Show” and Ann Marie of “That Girl,” both redoubtably trying to make it on their own. Following their lead, I swaggered off to college (where I knew no one) without looking back; then to New York City (where I knew no one) and San Francisco (ditto), refining my adult self with each jump. Certainly, I kept in touch with a few true old friends, but no one else — thank goodness! — witnessed the many and spectacular metaphoric pratfalls I took on the way to figuring out what and whom I wanted to be. Even now, time bends when I open Facebook: it’s as if I’m simultaneously a journalist/wife/mother in Berkeley and the goofy girl I left behind in Minneapolis. Could I have become the former if I had remained perpetually tethered to the latter?