In the Tall Grass

[Don Quixote] thought that every windmill was a giant. That's insane. But, thinking that they might be, well... All the best minds used to think the world was flat. But what if it isn't? It might be round. And bread mold might be medicine. If we never looked at things and thought of what might be, why we'd all still be out there in the tall grass with the apes.

from the movie They Might Be Giants (1971)