Unless you've been trapped under a sofa for the past couple of days, you've no doubt seen your friends posting their Facebook "A Look Back" movies, or have shared your own. This genius little marketing ploy to celebrate Facebook's birthday this week ("Facebook is 10!") automatically puts together a video slideshow of your photos and updates, set to soaring music, beginning with your very first profile picture, leading into your "first moments" on the site and most-liked posts, photos you've shared, and winding down with a photo collage that puts one of your recent profile pics at its center (though not always most recent, as a friend discovered when the profile pic wasn't a snapshot of...her).

"Help, My Kid Didn't Make My Facebook 'Look Back' Movie!" 34047

I don't know how you feel about your "lookback" movie, but I found mine to be surprisingly stirring—like watching a touching commercial about your own life, as others have pointed out—and balanced among my personal moments, work highlights, and especially my three kids and husband, which is waaay more than I can say for the state of my photo albums. (My oldest child has five leatherbound albums from his first year alone. My youngest has one slender photobook.). Watching the little movie that Facebook made for me, it was gratifying to remember some of the best moments during the six years I've been on the site, especially the addition of our third child and landing my job here at Parents.

But since Facebook's algorithm picks the pictures and updates it wants for you, these mini-documentaries aren't always an accurate depiction of what's most important to you. For one thing, since the algorithm favors "likes," a tool that wasn't even around in Facebook's infancy, the video's likely to include more recent pictures and posts than older ones. One friend says her daughter appeared in her movie several times, though the only photographic evidence of her son was in the form of birthday cakes she'd made for him. Another took a ribbing for numerous pictures of her cats, while her husband didn't make the final cut. (Whoops!) Another friend is surprised the movie entirely missed the birth of her twins. Sadly, depending on how the story of your life has unfolded since you joined Facebook, there's also the potential for pain: A friend who recently divorced said it was very hard to look at the smiling pictures of family life with her husband, back when none of them knew what was coming.

For friends who are happy about their movies and to share them, I've enjoyed viewing these little stories of their lives. (According to Facebook, "hundreds of millions" of Look Back videos have been made so far. And in a sure sign of their widespread success, they're already being parodied.) Some bloggers are saying no one cares about your Facebook history and you can keep your dull Look Back video to yourself, thanks. But as someone old enough to remember being subjected to hours of home movies of relatives in Ireland sitting around a living room with a ukulele "being funny," I know boring—and I applaud this tremendous improvement. The videos are short, sweet, and you can click on them at your own leisure, and tonight I plan to catch up on many of them with a glass of wine and my tablet in my lap. Watching friends' pictures of children and birthdays and graduations flash across my screen, I've found myself welling up. (That music gets me every time!) If you didn't like your video so much, there's good news: Facebook plans to add an editing feature in coming days, so you can update your own movie with what you like (and not what Facebook "likes").