When we first saw The Incredibles the day it came out last November, we thought Violet sounded awfully familiar, so we looked her up and found out she was played by someone named Sarah Vowell. She wasn't in anything except The Incredibles, so we figured they probably got someone Violet's age who hadn't done anything else, and that we were imagining that her voice sounded familiar.
When Aurora came up here last week and we were driving around doing stuff, I don't remember why exactly, but I brought up the book Assassination Vacation, which we knew to be written by one Sarah Vowell, because we saw her appear on the Daily Show fairly recently to promote it. That was the second time we had seen her on the Daily Show.
So then while Athena was setting up the DVD player last night so we could watch the Incredibles, I'm looking at the list of extra features, and it lists one called, "Vowellett - an essay by Sarah Vowell." I remember wondering why they would specifically include an essay by the voice of Violet, because I still thought she was played by someone her age.
It wasn't until we were looking the movie up on IMDb again (because we always do that after watching a movie we haven't memorized) and Athena sees the name Sarah Vowell (there was too much fun animation to read all the credits, and besides, we had looked up the cast before) that I finally put 2 and 2 together.