Realization

She thought about his question for a moment laying next to him in the dark. "I can't say for sure. Might have been when I was thirteen. Could have also been when I turned twenty-one. That's one of those things you never really know for sure." He said, "Losing your virginity is something you definitely know for sure." She chewed on her lip and asked, "Is it?" Then she said, "Then I guess I'll go with when I was thirteen."