You shouldn't emphasize things in the past.
Sarah's kids asked for an entertaining story to pass the time.
Sarah wants to tell a fun story.
Sarah makes up a story, drawing from a bunch of fantasy books she's read for inspiration.
Sarah decides to tell the kids a story about what she did 20 years ago that she's told them numerous times already.
Sarah's kids are highly entertained, and compliment her story after it's finished.
The kids get bored and leave while she is talking, not wanting to hear it.