The speaker starts with a familiar romantic idea: meeting someone and feeling they are your "other half." Almost immediately, they push back. If you need another person to be whole, you were never whole to begin with, so the phrase doesn't quite work. They offer a better word: "match." A match isn't a missing piece but an equal, someone who complements you and challenges you, makes you laugh and also frustrates you.
What matters most to the speaker is the range of feeling this person brings out. The "whole gamut of emotions" isn't only the pleasant ones; irritation counts too. All of it proves "you're alive." The final line, "To feel everything is everything," suggests that intense feeling is the point of a close connection.
The mood is warm, reflective and a little playful. The speaker sounds like someone thinking aloud, correcting themselves mid-thought, which makes the poem feel honest and conversational rather than sentimental.