Although Robert Graves's "The Cool Web" starts off with the phrase, "Children are dumb," Mr. Graves isn't here to talk smack about the intelligence of young people. Rather, he uses "dumb" in the older sense of not being able to speak. As the poem continues, Graves turns to "us," which is supposedly the adults who are reading his poem. Unlike kids, it turns out, we have the ability to use words and language to turn our experience into information that we can communicate to others. But when we do this, we end up losing out on all the stuff that isn't captured by language. On the one hand, the good stuff we experience isn't quite as good. But on the plus side, the bad stuff isn't quite as bad, either.
When it comes to turning our experience into words, Graves claims that there's a "cool web of language" that we all get caught in as we grow up. It's a web because it's delicate and flexible, but also impossible to escape from, just like language. On the other hand, it's cool because of the way it tends to take away the extremes of experiences.
It seems as if Graves is going to get all nostalgic on us, but he actually goes the other way in the final stanza of this poem, saying that we need language to organize our thoughts and experiences, or else we'll go totally bonkers from all the randomness. In the end, Graves basically tells us we're caught in a double bind as humans. We can't experience life to its fullest because language has a dulling effect on our experience, yet we'd also go totally crazy without this dulling effect. Yay?