We call that "Creeping Excellence", which is the act of going back over a completed design and finding ways to make it better, and you always can find something; make it cheaper, last longer, look better. It feels good, but if you never get your product to market... Another aspect is finding such an elegant solution to a particular knotty problem, you feel you have to somehow upgrade the rest of the product to that level of excellence. The key, and it only comes with experience, is when to say "This is good, and its good enough".
We call that "Creeping Excellence", which is the act of going back over a completed design and finding ways to make it better, and you always can find something; make it cheaper, last longer, look better. It feels good, but if you never get your product to market... Another aspect is finding such an elegant solution to a particular knotty problem, you feel you have to somehow upgrade the rest of the product to that level of excellence. The key, and it only comes with experience, is when to say "This is good, and its good enough".