Why do memories hurt so bad?

I have to believe there is some purpose... some reason

I wrestle now with the fact that they're gone
How long must this pain deep inside me live on?
It seems every day now I have to pretend
As I stand here, waiting for it all to end.
Words to explain only conceal
They can't tell half of the pain I feel.
And yet, I am torn.

Trapped in this place of sin, I long to go home
Even with You beside me, I can still feel alone.
But then I see those You've placed in my life
They need me through their pain and strife
And I don't want to leave them.
Still, I am torn.

Why did You give me a heart like mine?
I don't want these emotions all the time!
I feel the pain that others feel
I hold it inside so maybe they can be real
Unswerving loyalty, then I am abandoned
Deep compassion, so I am crushed
Even now, I am torn.

Through it all, it seems that I must
Despite my weakness, learn to trust
I will be the woman God made me to be
And hope that one day I will see
Some reason for the pain.
Until that day, I continue to be
Torn.