Instead of explaining love, the speaker simply points to it. Each of the first four lines names an ordinary moment: you walk into a room, I look at you, I hear your voice, I touch your skin. The repeated "It's love when" works like a heartbeat, and it makes love feel less like a big idea and more like something the senses pick up one moment at a time.
The ending changes the rhythm. The lines get shorter and slower, and the speaker admits something almost like wonder: "And don't know that I have ever been." The sentence is a little tangled, but the sense seems clear. Whatever the speaker feels now is so new or so strong that nothing before it compares. The mood is tender, simple, and a bit dazzled. There's no drama here, just someone trying to say how much a person's presence changes everything, and finding that plain words are enough.