Everything goes around in circles because we hit walls and obstacles, work around them and move on. Then at a later date, when we hit new walls and obstacles,

Everything goes around in circles because we hit walls and obstacles, work around them and move on. Then at a later date, when we hit new walls and obstacles, we re-visit old areas, many times to find that they are no longer problems (faster hardware, more network capacity, algorithmic breakthroughs), and so the industry half-pivots in a new direction. Everything old is new again. Wash, rinse, repeat.