A small, ordinary act, cracking an egg, turns into something close to a miracle here. The speaker expects the usual yolk and white, but instead finds a "broad water," a "fleet," and "a little room." Those images keep growing and shrinking at once: an ocean and a ship-filled horizon on one hand, a cozy indoor space on the other. The egg seems to hold both the vast and the intimate.
The title, "Ab ovo," is Latin for "from the egg," a phrase that means "from the very beginning." That fits the poem's sense of origins, of a world starting up inside a shell. The speaker doesn't try to explain any of this. The last line, "of which / I am very glad," is plain and quiet, almost shy, and it's the emotional center. The mood is one of gentle wonder and gratitude. Nothing dramatic happens, yet the speaker seems delighted to have stumbled on a hidden space that feels like a small, private shelter.