Or maybe the reason I have this random memory is as a trade-off my brain made — because I can’t remember what I desperately wish I could: details of the night my mother disappeared.
-- Narrator (Part 1: Chapter 1; Jenna paragraph 4)

Importance: Jenna can remember her mother giving her a taste of cotton candy and calling her sweetheart in Xhosa when she was only nine months old. She can’t remember, however, the memory of her mother that she wished she remembered the most, which was what happened the night her mother disappeared.

She taught me, even in absentia, that all good science starts with a hypothesis, which is just a hunch dressed up in fancy vocabulary. And my hunch is this: She would never have left me behind, not willingly.
-- Narrator (Part 1: Chapter 1; Jenna paragraph 12)

Importance: As Jenna began her search for her mother, her hypothesis is that her mother loved her enough that she would not have left her willingly.

However, her...
-- Narrator (Part 1: Chapter 1; Jenna paragraph 154)