Why at the beginning of human history there was a long time between the most important

Why at the beginning of human history there was a long time between the most important discoveries, and then they began to occur more and more often?

At the beginning of human history, people did not often make discoveries that were especially significant for themselves. Gradually they became involved in various activities. They had new tools and items to improve their lives. Slowly they moved to new territories. Over time, useful discoveries were made more and more often. This is due to the increased interest of people to improve themselves and the world. The impetus for new inventions was given by old knowledge, which served as experience, as a basis for activity. This is how scientific revolutions and geographical discoveries took place.