Beginning Stage: These newly weds are only starting their life together, so they only need a small apartment. They just bought a new couch.
Childbearing Stage: A few years later, this couple is growing their family. With a toddler and another baby coming soon, they moved into a two bedroom apartment. They took their couch with them to their new home.
Parenting Stage: As their children began school, this family moved into a three bedroom house so that their kids had room to run and play. They moved their old couch with them.