The phrase "how perfect you are to me" emphasizes the personal and subjective nature of the speaker's admiration and love for the person. It suggests that the person's qualities, characteristics, and essence align perfectly with what the speaker values and cherishes.
The declaration "No one will ever know" underscores the uniqueness of the speaker's perspective. It implies that the depth of their admiration and the extent of the person's perfection are so intimate and personal that they cannot be fully understood or appreciated by others.
In essence, this statement beautifully celebrates the idea of a love that sees the person as truly perfect and exceptional, irrespective of any external judgments or standards. It highlights the deeply personal and unique connection between the speaker and the person, where their qualities and essence are cherished as flawless and unmatched.