"When I Heard the Learn'd Astronomer" is frequently taught in introductory poetry classes. We have a sneaking suspicion that poetry teachers love it because it takes not-so-subtle digs at math and science. (Can't we all get along?) Leaving that aside, the poem does not use complicated language. In fact, one of its major themes is that a fancy education isn't necessary to appreciate the wonders of the world. Whitman is always more complex than he seems (which is not to say difficult), but an average reader will have no problem plumbing the depths of this gem.