Earlier quoted context omitted.
Right there with you. We sold our 1800sqft single-family for a 1500sqft townhome shortly after the kid flew the nest. And we still have two bedrooms that are seldom used (one is a guest room, used 3-4x/year, the other is an office used never, except by the dog).
My wife and I have a 2k square foot, 3 bedroom house, along with a kid (11 years) and a dog. (We recently moved there from the city) We're trying to figure out what we're going to do with all that space when kiddo is gone. Even though that's a way off, the likely plan is to downsize to a 2 bed in the city.
It's easier for some people to blame others and hold on to nostalgic knick-knacks, then maintain good relationships.