Why haven't more people seen this movie? It's wonderful. The plot is simple, a couple parting and then getting back together, the uncertainty of their relationship causing trauma. But through the whole film you do not feel that the situation has been over-dramatized; it is what it is, and that's why it's such a rewarding story. Rob Reiner and Penny Marshall made this film before their divorce; you can see the love of that relationship play out on the screen, and in that way, this is a bit of Hollywood history. There are some wonderful cameos, of the more noticeable being Michael McKean in a very early performance outside of "Laverne & Shirley" (he had connections, of course).
This is Rob Reiner and Penny Marshall before parting ways, and this is a truly romantic story that doesn't need to end on a sour note to succeed. If you have an opportunity to see it, don't pass it up.