How I Met My Husband

"So I said yes, and I went out with him for two years and he asked me to marry him, and we were engaged a year more while I got my things together, and then we did marry." -pg. 146

If I would have skipped over this sentence, I would have missed the whole point of the whole book. The title is even reliant on this one line. How can she put so much important information in one sentence at the end of the story? My reaction from this surprise ending is, well, surprise. I don't understand the point of this whole anechdote from when she was fifteen in order to get to the main point of the story. Then, the main point comes in once sentence. I think the point of the story was to show the gap from naive to mature. However, her mature life was described in one sentence. Maybe that's just the style the author wanted to take.