GREENWOOD VILLAGE — Don’t ask me why, but the only song I know all the words to — correctly — is Rick Springfield’s “Jessie’s Girl.”

I blame the ’80s.

You should know, I’m one of those songbirds who hits the notes just a tad off key. It’s for this reason that you’ll never catch me singing karaoke in public. Shoutout to my friend Sue Gibbons, though, who recently coaxed me into a private sing-along — and, you guessed it, I sang “Jessie’s Girl.”

I might be a shy singer, but catch me in an elevator, a car or a grocery store aisle with Rick Springfield on the loudspeakers and I’ll be giving an impromptu performance of “Jessie’s Girl” with full-body dance moves and zero shame.

The association runs so deep now that whenever “Jessie’s Girl” plays, friends and family — Leisa and Britt Thornhill are among the most enthusiastic — send me videos of themselves singing it to me. It’s basically my unofficial anthem.

After years of singing it solo, for the first time I finally heard Rick Springfield play it live at Fiddler’s Green Amphitheatre in Greenwood Village on Thursday.

The warm-up acts — John Waite, Wang Chung and Paul Young — each brought a nostalgic set, loaded with cheesy graphics and throwback video clips that sent me straight back to my childhood. It was the perfect setup for Springfield’s “I Want My ’80s Tour.”

And it was magical.

I’ve never belted out “Jessie’s Girl” alongside so many would-be singers just as enthusiastic as I am — though I’m pretty sure our reasons for loving the song aren’t the same. At least they seemed to know the lyrics to the other artists’ songs.

Not me.

Here’s how bad I am: I was today years old when I realized Jack Hues has been singing “rip it up” — not “whip it out” — in Wang Chung’s biggest hit, “Everybody Have Fun Tonight.”

I couldn’t stop thinking about the comedy bit Leanne Morgan does about attending concerts post ’80s. (She calls it “going to concerts with old people.”) With her Southern charm, she perfectly captures the middle-age wiggle: when concertgoers of a certain age (guilty!) dutifully rise for a verse or two, only to collapse back into their stadium seats exhausted.

My sidekick for the evening, Angela Cortez, and I made a game of spotting “unicorns” — fans we guessed were under 30 — in the crowd. (Spoiler: not many.)

At 75, Rick Springfield still (mostly) sounds how I remember him from his Working Class Dog album in 1981.

But I did, momentarily, think he was hitting the sauce a little hard after taking a swig and plugging his Beach Bar Rum — the brand he co-owns with Sammy Hagar (of Van Halen fame), who also co-wrote one of Springfield’s early hits, “I’ve Done Everything for You.”

His second swig, as it turns out, was actually oxygen.

He’s every bit as self-depreciating as a diehard fan would hope, calling himself “a lowlander” and poking fun at himself and the altitude.

Cindy Knoch last saw Rick Springfield as a blushing 11-year-old girl at the Pontiac Silver Dome in Michigan. The 54-year-old Aurora resident turned giddy all over again meeting the Aussie rocker Thursday night.

“He looked up at me and I thought, ‘Oh my gosh, I’m staring Rick Springfield in the eyes,’” she said.

It wasn’t the sold-out stadium these acts were probably used to in their heyday. But still a fun trip down memory lane.

Fiddler’s Green is the largest outdoor amphitheater in the metro Denver area. The venue seats 18,000 people. There weren’t that many there Thursday. No tickets for the cheap seats on the green were sold.

The evening turned into a full-on Throwback Thursday, with fans rocking armfuls of Madonna-style bracelets — one even wore a “Like a Virgin” gown — and Jane Fonda–inspired leg warmers. (I kept calling them “Olivia Newton-John socks,” and Angela corrected me every time.)

After all these years, Rick Springfield was worth the wait. And Jessie’s girl? I’ve been into her since 1981.