Why do second chances exist?

Why do second chances exist?
 
I know. I know the pain. 
I know the supressed crushing feeling of your heart which ravenously struggles to beat inside your aching chest.
It murmurs as you try to catch your breath and tiny crystals dance down your cheeks, sad in their own way.
It almost feels as if it longs to squeeze out,
Tearing. Ripping. Shredding your flesh,
Leaving the place in which it was once situated hollow and lifeless making the pain live no more.
 
But it can’t, and it won’t, it will only struggle,
No matter how much you want it to, your heart will not fail you yet.
It wants to carry on, but your mind does not, 
It wants a second chance, but you do not.
 
Your mind simply keeps echoing words to describe them;
Untrustworthy, careless, reckless… Abuser. 
You just want to end it all here and there, 
But no, you cannot.
 
For your heart is so magnetic to theirs, that you are forced to comply and return to their arms,
Giving them a second chance to ruin you all over again,
They say it’ll never happen again, yet you know it will.
So, you simply ask yourself;
“Why do second chances exist?”
 
 
(Quick disclaimer: this poem is not based off of true events)