Facebook’s On This Day feature reunites users with their old posts on the social network. For 20-somethings, that may mean a lot of embarrassing high school and college photos. An average of 115 million people receive notifications to see their memories every day, but there’s a segment of the Facebook population that is left behind.

“I've always felt like the kid who couldn't go on the field trip because their mom didn't sign the form,” Katie Wendorf, a biologist and this reporter's college roommate, said in response to a query about not having access.

In fact, every day at the top of my own News Feed I see, “Kerry, we care about you and the memories you share here. We thought you’d like to look back on this post.”

Wendorf never sees such a thoughtful note. If she goes to Facebook.com/onthisday — a page that 60 million people visit each day — she sees, “Katie, thanks for coming to check out your memories. Currently, this feature isn’t available to everyone.”

She isn’t alone. From a quick survey of friends, I found two others without access to On This Day. A cursory Twitter search of “Facebook on this day don't” brings up at least four more.

The absence would not be that surprising were it not 14 months since the feature was released. Most updates on Facebook take time to roll out. For instance, Facebook Reactions — the expansion of the "like" button — did not appear for every Facebook user on the first day of its release.

Facebook did not respond to a request for comment.

On March 24, 2015, Facebook announced On This Day via a blog post. “Today we’re announcing On This Day, a new way to look back at things you have shared and posts you’ve been tagged in on Facebook,” the post reads.

Like most Facebook features, On This Day was tested with a small group of Facebook users. At the time of the release, Facebook said it would “begin rolling out globally on web and mobile,” according to the blog post.

facebook not available Pictured is a screenshot of what appears on the desktop version of Facebook for those who do not have On This Day. Photo: Facebook

Facebook has even expanded on the feature’s design, which now is much larger, colorful and playful, as illustrated by Business Insider on the first anniversary of On This Day. In October 2015, Facebook introduced filtering options. Facebook users who have access to On This Day can now block specific people and ranges of dates from appearing in the shared memories.

Still, Facebook users who have On This Day cannot turn it off; there is no disable function. Facebook users can click on each memory and select “Hide post,” just like anything in the News Feed, but that does not mean a post will never appear.

For a social network that is facing a decline in original sharing, as the Information reported this year, such a tool could inspire some more engagement from users. Regardless of feeding into Facebook’s money machine, On This Day was a publicly promised feature that has yet to reach all of the network’s 1.6 billion monthly active users.