Ask a new couple how they met and you'll get a five-minute story, told with enthusiasm, from both sides. Ask a couple five years in and you'll usually get a one-line summary. The details don't disappear because they stopped mattering — they just stop getting told.
A few prompts to bring the story back out:
Our Memory Lane quizzes are built around exactly this — questions about how you met and what's happened since, so you both answer separately and see how your versions of the story line up.