Lyrics:

She was my once in a lifetime
Happy ending come true...
Oh, I guess I should have told her
I thought she knew...
She said, I took her for granted
It's the last thing I would do
Oh, I'll never understand it
I thought she knew... (I thought she knew...)

I thought she knew my world revolved around her
My love light burns for her alone
But she couldn't see the flame
Only myself to blame
I should have known...
I should have known...

A heart full of words left unspoken
Now that we're through...
I'd sell my soul to have this silence broken
Oh, I thought she knew (I thought she knew...)
I thought she knew

I thought she knew my world revolved around her
My love light burns for her alone
But she couldn't see the flame
Only myself to blame
I should have known...
I should have known...

She was my once in a lifetime
Happy ending come true
Woah, I guess I should have told her
But I thought she knew (I thought she knew)
I thought she knew... (I thought she knew)
I thought she knew (I thought she knew...)
Ooh... (ooh...)

Oh, I thought that she... knew...
Lance: Knew..., JC: knew..., Joey: knew..., Chris: knew...
Lance: Knew..., JC: knew..., Joey: knew..., Chris: knew...
(Justin: yeah, ooh...)