Stunning Rate of Development

I'm reading through your change log, and I'm simply stunned at your daily output. Even your website was apparently designed in a day! I was software engineer and graphic artist, for nearly thirty years, and was renowned for my speed and productivity. I'm now two years into making a computer game, which I work on constantly, daily - but I am NOWHERE NEAR as productive as you. I'm genuinely in awe and would be fascinated to have some insight as to how you manage this, in terms of waking/sleeping/working hours, and how you keep fit and mentally agile.