When I sent friends and fellow writers notes about the final decision on the title of my memoir -- Seven Wheelchairs: A Life beyond Polio -- I included a note that offered the opinion that my memoir did not come together, at least in the eyes of the editors, unless a writer learns to "see himself living a life with a rational, non-repetitive narrative arc, but he best find one if he wants to be published."
A writer friend replied " ... how would you explain narrative arc ... "
My opinion ...
A chronological narrative would have a "time arc," and so I think you'll be fine with that. I wrote the book as a "memoir in essays." I would pick up a subject about disability, look at it from every direction, and write about it. I had essays about the disease; its treatment; the hospital environment; the rehabilitation environment; isolation upon my return home; about education and employment; and more -- some like the "A Pot to Pee in" chapter that discussed the nitty-gritty of disability.
The editor said "Masterful essays, but there's too much repetition. Try a chronological narrative arc." I did, with the help of a "book doctor" because I felt too close to the material. Then the editor said "It's lost some of its passion. Make the chapters more like the essays."
There was the rub. It took me a long time to understand if anger and frustration occurred when I was in the iron lung at age 17 that I did not need to re-state the origins of that anger and frustration when I brought up an anecdote later.
What might help, really, is to outline anecdotes as you think of them on index cards. Then before you write, you might be able to shuffle the cards around into chronological order.
Next within the terminology of "narrative arc," I think, is the idea that we build our lives around themes. My theme was living as a person with a disability in 20th USA, but the sub-themes are anger, and duality (the idea that poliomyelitis at 17 killed then-Gary and created crip-Gary, who is an entirely different bag of tricks) and a prosaic existentialism.
How that might translate in another writer's life I cannot say, but I know this: we are different people to each individual we know, both because of their perceptions and because of the way we reveal ourselves to them.
With that, there are an infinite number of stories to weave into any narrative arc.