No, you made yourself quite clear. What I am saying is that it wasn't actually substantially less frequent. There were lots of frequent changes but the further we move away from them, the more they blend together. Both our lives grow more different, meaning it is more difficult to understand what these changes meant, and the records of these changes become more scarce. Basically if you showed a medieval peasant a palm pilot and an iphone, they'ed see that they are different things but they wouldn't really understand just how much changed between them both in terms of how difficult the technology was to develop and how influential those changes were on our lives. Likewise we struggle to comprehend the intergenerational variation in their lives. But since around the year 800 you have a pretty consistent rate of 3-5 major revolutionary breakthroughs of the same caliber as the steam engine per century.