One need not have lived long, for example, to have seen the spread of personal computers, microwave ovens, and videocassette recorders. These innovations alter how we live, just as life in the early 20th century was altered by, say, automobiles and telephones. Human societies always have relied heavily, for survival, on the making and using of tools.
Teeth are hard and sharp, but very limited.
Consider the difference between a stone chopper held in your hand, and an incisor tooth held in your gums. The energy driving hand tools is generated in the human body. The first genuine departure, in this respect, occurred only with control over nuclear power achieved a few decades. In future decades, controlled fusion could become a practical energy source. Meanwhile, we must cope with the fact that nuclear power's unprecedented potential for destruction places our very survival in doubt.