And why not use human symbols? It's what we know best. In fact, I doubt that we could even imagine a race/universe that did not somehow reflect the one we know. If we could we couldn't communicate it as there would be no referents. Even the "speed of thought" is only, at best, 390 feet per second. It seems fast only because neurons are so closely packed inside a human body but we have nothing else to compare it to.

We reason in this area by analogy.