Last July, I took a day off from work to get my car’s oil changed and accomplish a few other mundane things.

Originally, I had wanted to see a concert by the rock group Radiohead at Madison Square Garden, but could not break through what I call TicketMaster’s “wall of no” when tickets went on sale the preceding March. Even though I logged on the moment tickets went on sale, I could not get through to buy them. By that day in July, I resigned myself to the fact that I would again miss Radiohead, and concentrated on enjoying my day off.

Then on Facebook, something amazing happened. I saw a photo posted by Adam, an old friend from high school. Adam had tagged another friend, Jeff. I remembered Jeff making me laugh during a ride home to Queens from a Grateful Dead concert at Nassau Coliseum in 1970s. I commented on the photo, and was surprised when Jeff himself joined the conversation. We exchanged some recollections of that time.

After my errands, I went through a box of old concert ticket stubs and other memorabilia. I found a creased and yellowed note Jeff had written on loose-leaf paper during that car ride. It was a spoof in which he pretended to be a 1970s rock star writing to a fan. I sent Jeff a photo of the note.

Jeff was delighted that I had saved it. We chatted a bit more about music and concerts, and I said I had tried to secure a Radiohead ticket for that very evening, but failed. Minutes later, Jeff wrote, “Hey Robin. I got you a ticket for Radiohead tonight. Just felt like doing it for the good memories you brought me back to. If you give me your email address I’ll send it over. Ciao and enjoy! Jeff”

My first thought, “Is this guy crazy?” followed by, “Did he turn out to be a multimillionaire?”

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“Are you kidding me??” I replied. “You cannot be serious.”

He emailed the ticket — but my printer was out of ink. A frantic trip to Longwood Public Library solved the ticket-printing issue, and a quick perusal of the train schedule solved my transportation concerns. On the Long Island Rail Road, I spotted a friend also going to the show, so I had a seatmate for the ride to Penn Station. I fretted to her that the ticket might be phony. After all, Jeff lives in another state and apparently bought the ticket from a third-party seller. (He did not charge me.) What if I got turned away from Madison Square Garden?

I decided to be brave. Good karma was in the air. Sure enough, I had no problem at the gate! I saw the exalted Radiohead for the first time in my life!

I texted Jeff from my concert seat to thank him. This night would rank among my top 10 concert experiences. Jeff said this was a spur-of-the moment act for the happy memories of that night when we were teens.

So I have to say I’m very grateful for social media. I never expected a Dead concert from decades ago to link me a 2016 Radiohead show. What a long, strange trip it’s been, indeed.

Reader Robin Ames lives in Coram.