The polished wood square is pale and smooth, about the size and thickness of a credit card. It unfolds like an accordion, revealing three panels. In fine calligraphy is The List I made long ago. It’s all the attributes I wanted to find in the person I’d fall in love with. It’s my Ninety-Nine Things List, and Ryan checks off every one.

I’ve been told that most girls learn about love from their moms. But the summer I turned ten and my brother, David, was twelve, my mom was diagnosed with Hodgkin’s lymphoma. She went fast, which everyone says is a mercy, but it isn’t. It just about killed my oncologist father that even he couldn’t save her.

My mom was a pharmacoepidemiologist on the board of the National Academy of Medicine. She used to fly all over the world, sharing stages with Melinda Gates and Tony Fauci, giving speeches on infectious diseases at the CDC and WHO. She was brilliant but also warm and funny. She could be tough, but she also knew how to make everyone feel special, seen.

She died on a Tuesday. It was raining out the hospital window, and her hand seemed smaller than mine. I held it as she razzed me for the last time.

“Just don’t be a dermatologist.”

(When you’re born into generations of doctors, you make jokes about imagined medical hierarchies.)

“I hear there’s good money in it,” I said. “And the hours.”

“Can’t beat the hours.” She smiled at me. Her eyes were the same blue as mine, everybody said. We used to have the same thick, straight brown hair, too, but in so many ways, my mom didn’t look like my mom anymore.

“Lanie?” Her voice had gone softer and yet more intense. “Promise me,” she said. “Promise to find someone you really, really love.”

My mother liked overachievers. And she seemed to be asking, with her final words, for me to overachieve in love. But how? When your mom dies and you are young, the worst part is that you know there’s all this stuff you’ll need to know, and now who’s going to teach you?

It wasn’t until college that I was introduced to the writer who would teach me about love: Noa Callaway.

One day after class, I came back to my dorm, and the tissues were flying on my roommate Dara’s side of the room where she and her friends were hunched together.

Dara held a half-eaten Toblerone out to me and waved a book in my direction. “Have you read this yet?”