Tragic Hindsight

Fairly self explanatory.

While I should be writing goodbyes
I sit here and hold back the cries
For fear of the chances I've lost
And the incredibly painful cost
but yet I persist in this train of thought
for concentration can never quite be bought
But no matter how hard I try
My mind goes back to that girl
And each time, a part of me dies
Whenever my heart will whirl