The biggest factor for me, by far, has been an understanding spouse. That being said, what I've learned doesn't require that luxury. Since having our first chi

The biggest factor for me, by far, has been an understanding spouse. That being said, what I've learned doesn't require that luxury. Since having our first child I've learned, painfully, to stop trying for optimal conditions (a quiet room, a guaranteed, contiguous block of uninterruptible time), and learn to spin up and down quickly as circumstances dictate. That learning process was primarily about refusing to use sub-optimal conditions as a reason to delay work, but it's also about setting up in the family room and accepting that people make noise and demand attention and that, with mental discipline, you can work through it. Copious notes (I keep a running 'dev log' open and note my thoughts into it almost constantly) are a huge help in re-establishing context after a distraction. There's always something you can do to keep engaged with the codebase when given a 30m slot: some brainless extraction of magic numbers into statics; cleaning up some nagging compiler warnings; things that free you up to do more creative and challenging things when there's less noise and distraction later on.