It could happen in the morning. Or the middle of the night. A quiet group of people — cooks, technicians, nurses, doctors, administrators — line a hospital hallway to acknowledge the passing of life, the death of someone who has chosen to become an organ donor.

The patient room I enter is quiet. It’s late morning, and I’ve walked here from my desk at the other end of the hospital after receiving a text message that says I’m needed. I feel uneasy at first, an interloper in a space that’s unfamiliar. But the nurse I meet in the room is grateful I’ve arrived and tells me so. Then she talks with me about her patient, who is in the bed near where we stand. His name is Frederick. His eyes are closed, his body still, his breaths shallow.

My story is about neuroplasticity and mayonnaise. I spent the greater part of my 20s living in Dublin, where I was working on a doctoral thesis in history and where mayonnaise comes in glass jars. While growing up, I had lived in just one St. Louis house. In Dublin, I was on the move, quite literally, living in three different apartments and one guest bedroom over four years, thanks to Dublin’s turbulent rental market. For the most part, I did my moving on my back and on my own.

Do you want to know if you’ll develop Alzheimer’s in the next 10 years? This is the question i’m faced with daily. My name is Marty Reiswig, and my family has been studied for decades because we carry an extremely rare genetic mutation that causes early onset Alzheimer’s disease.