It seems only natural to regard your home, your family, and everything else you do as a development environment. It's all just one big project, isn't it?
When you look around your home, what do you plan to do? The SimplestThingThatCouldPossiblyWork? And then ReFactor it? When you think about your relationship with your loved ones, don't you TestFirst? Your child's college fund - YouArentGonnaNeedIt, are you?
Seriously, if you and your loved ones acted more like a development team and less like a bunch of customers, don't you think you'd have a better time with them?