which piece is missing lyrics

I don't know much about the things that make you who you are
A couple of dozen stories, some snapshots from your childhood
But here in the dark it's clear that we both have our share of scars
Some only scratch the surface, some have sculpted who we are
(chorus)
I don't know which piece is missing from your heart
I don't know which piece is missing

Running around in circles...running into each other
I didn't mean to let you come too close for comfort

Chorus

Now that the shouting's over, try to accept each other
Faults you'll forgive a friend for are hard to take in your lover
And now that I sung about you and all your insecurities
You can take this song and sing it right back at me

I don't know which piece is missing from your heart
I don't know which piece is missing
I don't know which piece is missing
I don't know...i don't know...i don't know