The Parts That Stay

The rowboat had stopped drifting, or maybe it never really moved. The lake was that still. Maya trailed her hand in the water and watched the ripples go and not come back.

"My skin is peeling," she said. She held up her shoulder, pink from the sun. A curl of dead skin lifted at the edge.

"Everybody's does that," said Soren. He was lying across the middle bench with his knees up, watching the first stars try to get through the not-quite-dark.

"No, I mean it comes off. All of it. My whole skin, gone, and I grow a new one." She peeled a little more, carefully, the way you peel the label off a bottle. "So am I even wearing the same skin I was born in?"

"No," Soren said. "You lose the whole outside layer about every month. My cousin told me. She's in nursing school and she says it constantly."

Maya sat up. The boat rocked and settled.

"Okay. So the skin's new. What about the rest?"

Soren considered the ceiling of sky. "Blood cells. Those don't last. A few months, tops, then they get replaced. Stomach lining is even faster. Days."

"Days," Maya repeated. She liked the sound of it and hated it a little. "So the stomach I ate breakfast with is already gone."

"Mostly."

"Bones?"

"Bones too. Slow, though. Years. But yeah." Soren was sitting up now. This was the kind of thing that got him sitting up. "My cousin said your whole skeleton swaps out about every ten years."

Maya looked at her own hand in the fading light, turning it over. "So in ten years none of this is the same hand."

"Not one piece of it."

The lake made a small sound against the hull. Somewhere on shore, someone laughed, far away, made small by the water.

"Then who's the person," Maya said slowly, "if all the pieces keep leaving?"

Soren opened his mouth to answer and found he didn't have one. He liked that feeling less than Maya did. He reached into his jacket for the notebook, uncapped the pen, and wrote skin month / blood months / stomach days / bones ten yrs down the margin, one under the other, a little tower of things that leave.

"Wait," he said. "Not everything."

"What do you mean?"

"She said that too. My cousin. She was showing off, she said, there are exactly three things that don't. Three things you keep the whole time."

Maya went quiet. In the almost-dark her eyes were doing the thing where she was already somewhere ahead of the sentence. "Guess," she said. "Before you remember. Just guess what you'd keep, if you could only keep three."

Soren looked at his hands. "Brain. You'd keep your brain. Because that's the you part."

"Some of it," Maya said. "Right? Not all. Because you learn things and forget things."

"The thinking part," Soren said. "The outside wrinkly part. The cortex." He wrote cortex? "Those cells, I think, the actual counting-and-remembering neurons, I think you're born with them and that's the set. You don't grow new ones there. You just have them wear out."

"So the you that thinks is old," Maya said. "As old as you are. Exactly."

"Exactly as old," Soren said. "The neuron that's thinking about this right now has been in my head since before I could think."

Maya laughed, once, delighted and a little unsteady. "It was in there when you were a baby. Waiting. What's the second one."

Soren closed his eyes. He didn't want to guess. He wanted to be right, and guessing felt like the opposite of that. But she was waiting, so he guessed. "Heart."

"Why heart."

"Because it never stops to swap parts. It can't take a day off to grow new muscle. So maybe the muscle that beats is the muscle you started with."

"The heart cells," Maya said. "The beating ones." She pressed her hand flat to her own chest, not for show, just to feel it going. "Same ones. The whole time. Beating since before I was born."

"That's two," Soren said. He wrote heart muscle. His hand was not quite steady. "I can't get the third."

They sat. The stars were winning now, coming through in twos and threes.

Maya was looking at the shore lights across the water, and then she wasn't. She was looking at how she was looking at them. "Soren. When you look at a light really far away and it goes a little blurry and then sharp. What's doing that."

"Your eye. The lens."

"The lens." She said it like she'd caught something. "Is the lens meat? Is it cells?"

"It's cells. It has to be."

"Then does it swap them out?"

Soren went still. Then, quietly: "It can't. If it grew new cells in the middle of a lens, the lens would go cloudy. You couldn't see through new parts. It has to stay clear." He looked at her across the boat. "So it keeps the old ones. Forever. The center of your eye is the oldest part of you that you can point at."

"Three," Maya whispered.

"Three."

Maya turned and looked directly at Soren, at the shore behind him, at the coming-out stars, and she understood what she was doing it with.

"So right now," she said, "I'm looking at you through the exact same little window I looked at everything through when I was one day old. That never got replaced. It just got carried along."

Soren didn't write anything down. He was busy looking back at her, through the middle of his own eyes, the part that had been there the whole time, that had seen his mother's face before it knew what a face was, that was seeing Maya now.

"Everything else about us is on its way out the door," he said. "And these three things are just riding along the whole time. Keeping score."

Maya lay back against the bow and looked straight up. One by one the stars sharpened, then blurred, then sharpened again, as the oldest part of her let them in.