Why? Well I was mostly expired from a story in "Surely You're Joking, Mr Feynman" where he talks about being bored with physics, and he gets back into it by playing around with toy problems that he had to work out from first principles (the way that the wobble in a spinning plate precesses around the axis). So I've started programming in an emulator of this old 1980s computer. It seems to be working for me too - I'm finding myself to be much more engaged in my day job since I've started.