If this is for the best, then why is it so difficult?

Big Girls Don't Cry - Fergie

It's personal, myself and I
We've got some straightenin' out to do
And I'm gonna miss you like a child misses their blanket
But I've got to get a move on with my life
It's time to be a big girl now

Fairytales don't always have a happy ending, do they?
And I foresee the dark ahead if I stay

Like the little school mate in the school yard
We'll play jacks and uno cards
I'll be your best friend and you'll be my Valentine
Yes you can hold my hand if you want to
'Cause I want to hold yours too
We'll be playmates and lovers and share our secret worlds
But it's time for me to go home...