Change had to come, or we should all still be living in caves.

They used to say that because of the bombs we would go back and live in caves.

You have to live in caves and sleep on stones.

They, the politicians, must think we all live in caves and have very short memories.

Environmentalists don't have to live in caves to be good citizens.

This game has been going on since our ancestors lived in caves.

It's true that I've never had to live in caves, or wonder where my next meal was coming from.

"The rest of the world must think that we live in caves."

We may as well all go back to living in caves.

Without these radical new ideas, we would still be living in caves.