The speaker describes a teacher by comparing him to a flightless bird, and the comparison is both odd and affectionate. The bird can't use the sky, which looks to him like a book in a language he can't read. His huge eyes seem to promise sharp vision, yet they're no bigger than his three stomachs, as if his appetite for the world matches what he can take in. The three stomachs hint at an ostrich-like, even slightly comic creature, though the poem never names one.
The last lines turn the image around. Burying his head in the sand sounds like cowardice, but the speaker says it isn't an escape from the truth. It's a way of remembering it, by sitting alone with his fears. The mood is quiet and tender, with a little humor. The speaker seems to admire a teacher who is earthbound and imperfect, and who faces his fears in private rather than pretending he has none.