Families tend to move a lot, especially now when some loose their homes and must move and many parents get transferred or need to find jobs in other areas. Moving can be difficult for children because, even if they've only lived in the same place for a few years, that's a big part of their lives.
We have an advantage in our time. Unlike people in past centuries who wrote letters that might take months to be delivered, we can keep in touch through the internet and cellphones. But little kids can't use electronic devices very well. Even for older children and adults who can, video conversations like those on Skype are not really the same as face-to-face, real world contact.
It's helpful if sometimes families can travel to places where they used to live or invite people they knew in the past to vacation with them. And parents should encourage kids to keep in touch with old friends at least once in a while even after they make new ones. Although they may not appreciate doing that now, someday they'll realize the value of knowing people who share some of their memories.
Old friends really are the golden ones.