I recently received a direct message on LinkedIn from a woman in Iceland.

The woman, Sigridur Gunnarsdottir, wrote: “I’ve been following your writing lately and really enjoying it. The last piece I read was in your newsletter where you wrote about how hard it is to remember and how you regret not having kept notes.”

She explained that she could relate to the feeling after having spent a decade with her head down working in a stressful job at a hospital.

I get similar messages from people I don’t know and it’s always encouraging.

This time, however, was different.

Sigridur continued: “I spent the summer of 1985 in London and I have not kept in touch with people I met during that time. So my question is whether you might have spent that same summer in London?”

That stopped me cold. How could she have known?

I’ve never written publicly about working in a bar in London that summer and it’s not on my CV. It was in between my freshman and sophomore years in college.

Intrigued, I responded.

It turns out Sigridur worked as an au pair for the owners of a pub in Kew Gardens called the Kings Arms where I bartended. She was just 15 and spent most of the days upstairs.

The owners would periodically have her come down to tidy up the pub, so she recognized the staff. She had the foresight to write down everyone’s names. She also took photos.

She sent a picture of me wearing the pub’s weird floral uniform.

It was a shock that brought back memories. I didn’t have a camera that summer and have no other photographs, which is probably why I don’t think much about that time.

The exchange reminded me that the past is never reliably buried.

We’ve seen that in recent years with the discovery of Shackleton’s shipwreck near Antarctica and the digitization of church records that have extended family trees.

Online, Facebook facilitated the re-discovery of people you knew from college or high school. For me, that started with Americans in 2010 and gradually spread globally.

I went to high school in Norway in the 1980s and initially lost touch with everyone. I’m now reconnected with many of the class and hoping to attend a 40th anniversary this spring.

Sigridur and I texted via LinkedIn’s platform and then got on a Zoom call.

One of the unanticipated joys of being in your 50s is connecting with people who can shed light and provide perspective on long ago moments in your life.

We talked about the twists and turns of life. She did her graduate studies in Wisconsin and might have stayed there were it not for the disruptions in visas following 9/11.

She tried to find some of the other bartenders from the pub, including Roy, Michael and Jane.

But I was the only one she was able to find online.

She pointed out that in Iceland, a country of just 400,000, it’s easier to keep track of people. If you weren’t sure what happened to someone “you just call your aunt.”

I understand not everyone wants to post on social media.

But doing so can open up a surprising amount of insight.

It can connect you not just with the present, but the past.

And in the process, remind you what you did in the summer of 1985.