Wendy Berrell said it best: "You cannot carp fish without faith."
If you think the fish ate, you are too late, you should have set the hook. If you think about setting the hook, you are too late, you should have set the hook. In the time it takes for your weak, faithless mind to tell your body to MOVE...yep, you should have set the hook.
Carp fishing does not reward half measures. You have got to play for the win. You need to make the risky cast. You need to take an extra step closer to the fish. You need to put the fly 4 inches away, because 8 inches might feel safer but the fish won't eat it anyway. You need to risk it all to win big.
Bottom line...when carp fishing if you are not certain the fish ate...act with certainty anyway.
It took Travis and I half the day to remember these things, but we eventually got it together.