Despite being written under duress, the song became a global phenomenon, topping charts in the US, Canada, and Romania. It held the record for the most weeks on the chart (124 weeks) for years, surpassing the duo's own "Truly Madly Deeply". If you'd like, I can: Break down the specific lyrics and their meaning.
The music video added a layer of "destiny" to the song's story, featuring a young as Hayes' love interest.
The "deep story" of "I Knew I Loved You" is actually one of profound irony. While the song is celebrated as one of the ultimate romantic ballads of the 2000s, it was written in just 40 minutes out of "pure spite" toward their record label. The Spite Behind the Romance