When I was 6, I found independence in journeys to my grandfather's house, two blocks away. I would hop on my bike and head over for a mini Horizon chocolate milk.My brothers and I called him Dad-dad, and so did our friends. We knew we could stop by anytime for a treat, or for tea and cookies at 4 p.m. An accomplished woodworker, he finished an eave in his attic, intuiting correctly that it was a perfect space for forts."We "And a lot of goodies."Sam and a friend, Olivia, said nearly identical things when I asked about memories of neighborliness in Silver Spring, Maryland: "I was always being sent to a neighbor's to borrow ingredients" and "there was not a day that we were not outside."I