Love to Know the Rest of the Story

Sitting in the park, people watching, I see a father and his young daughter.
She says, 'You're going to be my best friend forever, Daddy.'
The father responds, 'You're my best friend forever too.'
She says, 'I love you' as she hugs his leg and he says it back.
What a perfect moment to witness. It made my heart warm to experience that even as a bystander.
A short time later, I hear a small child screaming 'let me go' as the father and child and coming back to their car.
What happened on their walk to ruin the innocence? Will she soon, as young children her age tend to do, forget and dad will be her best friend again? How long until they each feel the love they just experienced? Until someone else gets to witness another moment?
How many of these cycles has God experienced with humans? How many of these cycles has He experienced in each of our lives?
We each say 'I love you' and then, foolishly, humans turn our backs time and time again. And yet, God waits for us, patiently, with open arms, waiting to say 'I love you' once more.