During my late teens and twenties, I practiced a Korean martial art called Soo Bahk Do. One peculiarity that always struck me was its belt coloring system. The progress sequence was like other martial arts like karate where you start with a white belt and progress through different colors until you get to a black belt. Except in Soo Bahk Do there was no black belt. Their equivalent was a dark blue belt.
The philosophy was that perfection does not exist, that there is always a way to improve. Black represented an end state that could not be improved upon whereas dark blue left room for improvement, a continuous reminder to always keep working on your craft.
The same philosophy is a useful framework to think about continuous progress in business. There is no perfect end state to be achieved. There is only a continuous gap that can be filled between what you experience and observe today and a better version you are able to imagine and create for tomorrow.
In an agile product development process, there is no final sprint that gets you to the perfect product. There will always be new insights, customer feedback, technologies, regulation, competition that will create a new desired future state that needs to be worked on.
There is no such thing as a perfect process. There will always be ways, big or small, to improve the way a sequence of activities improves quality, speed or cost.
The only thing we can do is work on our craft to keep improving the way we assess where we stand today, develop the creativity and imagination to define a desired future state and have the courage and discipline to bridge the gap between both. As we hit new milestones our view of the gap to be bridged will keep evolving. Things that used to seem important may start to look trivial.
But that is the whole point. Progress is the way.