The speaker shrugs off the opinion of anyone who would call him slow, and then makes a case for slowness by showing it. He watches a slug glide over a rock and sees something wondrous: water flowing uphill, a magic carpet. He enjoys small, quiet things, like the way a yawn fills his head with the sound of surf.
Those pleasures are set against the "hiccups" of anger, pride, and shame, which the speaker treats as little spasms that interrupt life without adding anything. Even love gets the same treatment, described as a virus the body runs a fever to fight off. The playful, scrambled word "sam pee-body" suggests the sparrows have their own way of naming this, and it makes the speaker's tone gently self-mocking. The mood is relaxed, humorous, and a little tender. Nothing is rushed, and the speaker seems content to notice a slug, a yawn, and his own flawed heart.