Firstly, it suggests that before meeting this person, the speaker had not encountered someone who could truly connect with them on a profound level. The metaphorical language highlights the rarity and uniqueness of this connection.
Secondly, it conveys the idea that the person being addressed not only understands the speaker but is in perfect harmony with them, as if they are speaking the same emotional and spiritual "language."
In essence, this statement celebrates the exceptional connection and understanding shared between the speaker and the person they love. It signifies that this individual has a deep and intuitive understanding of the speaker's innermost thoughts and emotions, making them feel truly seen and heard in a way they had never experienced before.