Right away, the poem pushes back against a familiar idea: that a soulmate is the missing piece who completes you. The speaker rejects the "two halves of a whole" picture and says instead that each person is already complete. Love isn't about filling a gap. It's something two full people choose.
The second line is what makes the poem charming. After the slightly serious, philosophical first line, "love to nuzzle" feels soft and playful, almost animal-like, like two creatures pressing close for comfort. The word "nuzzle" suggests affection without pressure or need. The title, "Harbor," fits this too. A harbor is a place of safety and rest, yet a ship in it is still a whole ship, not a broken one.
The mood is warm, gentle, and quietly confident. The speaker seems content, even a little amused, and sounds sure that closeness is better when it comes from freedom rather than lack.