In this task, you're given an article and an answer. Your task is to generate the question for the answer based on the given article.

Article: Make new friends, but keep the old. One is silver, and the other gold. This song expresses a nice rule: increasing friends. Sometimes things actually work out that way. I've met adults who've said, "We've been friends since kindergarten!" A friend who has known you forever is a treasure. But friendships don't always last -- especially for children. When I was growing up, my family moved about every three years. The advantage of this was that I got to see different parts of the world, and it made my family very close. I also learned to be pretty good at making new friends, and, to keep in touch with old friends, I became a great letter writer. But I always admired those kids who stayed in one place and kept their friends for a long time. I didn't learn that children's friendships can disappear even when no one moves until I was much older, with children of my own. Sometimes friendships end in quarrels and hurt feelings. But perhaps the most painful end to a friendship is the one-sided rejection -- one friend turns away, or chooses someone else as a close friend, and the other child is left feeling sad and wondering why this thing happened. The end of a friendship is often sad, but it's not necessarily a bad thing. Often the end of one friendship makes more room for other friendships to grow.
Answer: Old friends are as important as new ones.
What does the children's song really mean?