Because

The speaker feels emotionally moved by simple facts of nature: the world is round, the wind is strong, and the sky is blue. These observations seem to awaken excitement, wonder, and sadness. The lyrics move between delight and tears, then connect those feelings with love, which makes the natural world feel personal.

The phrase “turns me on” can mean that something excites or energizes the speaker; here, it may suggest a strong, almost physical response to the world. “Blows my mind” means that something overwhelms or astonishes a person. The repeated lines make these reactions sound immediate and spontaneous, while “Love is old, love is new” presents love as both timeless and freshly experienced.

The song does not explain exactly why a blue sky makes the speaker cry, or why these ordinary facts bring such powerful feelings. The tears could suggest sadness, beauty, or emotion too strong to name. The line connecting love with “you” may address a particular person, but it also leaves room to hear “you” as a broad expression of love. The lyrics invite listeners to feel the mystery rather than solve it.