My favorites were short, punchy lines -- openings that set the stage just enough to intrigue and then set the mind adrift in story possibilities:
Let me apologize in advance.
I’m my own fault.
I lived south of I-80.
These genes don’t fit.
She hit me first.
Later, I looked through the published memoirs on my bookshelf. Most of their opening lines were long and immediately specific to the story at hand. But I found three that are general enough to serve as writing prompts:
The first day I did not think it was funny. (From Nora Ephron’s Heartburn -- reportedly such thinly disguised fiction that I’ll call it memoir.)
Here they come. (From Frank McCourt’s Teacher Man.)
Life changes fast. (From Joan Didion’s The Year of Magical Thinking.)