1. Agriculture. Agriculture birthed civilisation. Without the ability to farm, we would all still live in tiny barbarous tribes fighting over the field with the most dogs in it.
2. Writing. Writing exponentially increased the propagation of ideas and increased their lifespan. To the point where Six thousand years later on the other side of the planet I know what some Egyptians thought.
3. The Scientific Method. The Scientific Method gave us science. No longer were we natural philosophers speculating and experimenting in the dark. We were scientists. Boldly shining a light into the dark, unwraveling the mysteries of the universe in an endless quest to save creation of the tyranny of it's creators, be they gods or random chance.