I want to say something about revenge, because people who hear this story assume it is one, and I have had to think carefully about whether they are right.

There is a version of that Christmas, and everything after, in which the point was to make my family feel the cold.

To do to them what they had done to me — to cast them out, to strip them bare, to stand them in the metaphorical snow with a suitcase and let them freeze in the knowledge of what they had lost.

And I will not pretend that version did not tempt me.

On Christmas morning, standing in the actual snow, watching my father turn back into the warm and lighted house without me, every cell in me wanted, someday, to reverse those positions — to be the one inside the warmth, watching them shiver outside it.

But my grandfather had given me a harder and better idea, and it took me the whole year to fully understand it.