Who built the seven gates of Thebes?
The books are filled with names of kings.
Was it the kings who hauled the craggy blocks of stone?
These are the opening lines of Brecht's poem "A Worker Reads History." As he suggests, while it was the kings who demanded the structures built, it was the workers who achieved the task. They were the ones on the front lines having to come up with novel ideas about the "how to."
The meaning of the poem, as vangoghfan points out, lies in the questions readers are left with. The poem is meant to both enlighten and intrigue the reader.