No Quitting

I feel I need to try the PCT again because I am afraid that there is quit in me.  In my youth I never quit when it got rough.  I fought on and struggled but always finished no matter how hard it was.  Its the reason I was able to survive in the Marines. In boot camp, I struggled but i never quit.  I never gave in and I pushed myself hard and farther than I thought I could.  And now I dont feel that. I feel that I Have gone soft and that I couldn't finish it even if I really wanted it.  I need to prove to myself that I have that drive. That passion and motivation to push myself again.  That I wont quit when it gets tough and when I am tired and exhausted. I have to do this to prove to myself that I am no quitter.  If you quit at one thing, then there'll be another and another and the next thing you know you've quit at life!