Just watched at home with most of my kids.
I loved it, even though the nonlinear plot lets you know "this is not a love story."
What struck me: my courtship of Vonne in the summer of 1982 went a lot like this movie. The difference was, Vonne, while acting like my "Summer," fortunately turned out to be my "Autumn" in terms of outcome, meaning she became the Day 1 that forever-stuck after my 500 days with somebody else.
You'd have to see the movie to understand that statement.
I've always loved Zooey Deschanel and am consistently impressed with Joseph Gordon-Levitt (remember him from "Third Rock from the Sun?") needs to be appreciated in this role as a contrast to his much-more-serious-and-seemingly-older role in "Inception" (which I just watched for the fourth time on the flight over to Beijing!). Both were outstanding.
Only complaint: I felt the cinematography was kinda blurry--on purpose, and I like things super-crisp on contrast.