How big is too big?

I ride the local MAX (our light rail system) back and forth to work, and I am so entertained by some of the conversations I overhear from time to time. Some of them make me laugh, and others make me think.

For example, this evening as I was on my ride home, I overheard a man talking about his "giant" house. Apparently, he and his wife own a 4500 square foot house----for the two of them. They only use 50% of the rooms, and the master bedroom takes up the entire second floor of the house. They have a three-car garage, and the man stated that he didn't really like the town they lived in; it was too "country".

There were so many questions I wanted to ask (but couldn't, as that would have tagged me as an eavesdropper): Why did they buy such a big house? Were they going to have children, and thought they would potentially use all of that space? Were they going to be caring for aging parents soon? Why did you invest in such a large home, in a town you didn't like? How do they justify the money spent on electricity, maintenance, insurance, and other costs of heating/cooling/protecting the house?

I'm trying not to be judgmental of this man and his wife. Maybe they had really good reasons for buying the McMansion. Maybe they bought, and realized it was way too much house for them. Maybe they can afford it, and don't mind heating and cooling a 4500 square foot house when they only use 2250 square feet of space (by the way, a 2250 square foot house is still over twice as big as my own little abode).

I'm so grateful for my cozy little house----it's expensive relative to my income, and I may have to sell it and downsize sooner or later, but for now it's the perfect nest!