I had been so proud of my clever test.

I had been so sure he had passed it.

I had not yet understood that I had designed the wrong test entirely, and that the real one was about to be administered to me, in that bedroom, by his hand.

I want to explain the test, because its flaw is the whole lesson of my life, and I got it wrong in a way that is worth understanding.

My reasoning had seemed airtight.