I couldn’t decide what was more pathetic: the fact that a one-time teen idol was performing at the Boston Seniors & Boomers Expo, or the fact that I myself was attending the Boston Seniors & Boomers Expo in order to see him. It was a toss-up.

But I’m getting ahead of myself.

A few weeks ago, a confluence of seemingly unrelated events descended upon me. My husband emailed a review of a book by an author whom he knew I admired. I reconnected with a former colleague at a marketing conference. And I happened to see an ad for an upcoming concert at the aforementioned, rather embarrassing, venue. Suddenly all roads led back to a destination I remembered well from fourth and fifth grade…David—audible sigh—Cassidy.That’s right. Keith Partridge himself. He of the gauze shirts, slim hips, hairless chest, long, layered shag, and sweet, knowing smile. To an imaginative girl in 1973, he was an unattainable dream to be cherished. After all, in his own words,

“Cherish is the word I use to describe

All the feeling that I have hiding here for you inside.”

Today I am an almost-50-year old successful, self-respecting woman (of, I should hope, intelligence and impeccable taste). But I couldn’t resist Cassidy’s groovy siren song. I decided to position the entire thing as a multimedia concept exercise, my own mini-sociology experiment. I began with the book.

I Think I Love You (Alfred A. Knopf, $24.95) is the much-anticipated second novel by bestselling author Allison Pearson. Her celebrated I Don’t Know How She Does It reassured millions of overworked, underappreciated moms that they were (a) not going mad and (b) doing the best they could. It was recently released as a movie starring Sarah Jessica Parker. Pearson’s prose is crisp and smart; throughout that first book, you find yourself smiling, shaking your head in both recognition (“Oh, she’s right, all those judgmental PTA mothers are horrid!”) and wonder (“How did she think of that! But, it’s true, so true!”).

The second book follows the pre-teen adventures of one Petra Williams, growing up in a parochial village in South Wales in the 1970s. She is bright but insecure, hovering on the fringe of a mean-girls clique. She has a strict German mother. She plays the cello. And above all else, she is the world’s most devoted David Cassidy fan. She knows this absolutely because she has made it her life’s work to learn everything about him: his likes, his dislikes, his history, his hobbies. She wears only brown because, according to her magazines, it’s his favorite color. If it’s in The Essential David Cassidy, it must be true.

Meanwhile, we meet a young man, Bill, a recent literature graduate, who is the fanzine ghostwriter of Cassidy’s letters to his lovesick admirers. Pearson adeptly sets up the yin-yang of the disdainful author posing as teen idol and the young girl who hangs on his every word. The two meet by chance at Cassidy’s ill-fated London concert of 1974. In the book, as in real-life, the crowd of fans, coupled with poor event layout and management, resulted in nearly 1,000 injuries and the death by asphyxiation of a young British girl. By the end of the evening, Petra has lost a shoe, her mother’s trust, and her childhood dreams.

Fast forward to the present day. In part two of the novel, Petra is a grown woman with her own lovestruck tween. (This time, Leonardo DiCaprio is the object of worship: “I love him so much, Mum.”) Petra works as a music therapist and has been abandoned by her husband for a much younger violinist. Then again, Petra hasn’t been completely abandoned. The soon-to-be-ex actually brings her his dirty bedding to clean (apparently there isn’t a washing machine on the new girlfriend’s houseboat). And Petra does it! Can you say “doormat?”

Is it any wonder that this disillusioned woman of a certain age longs for the certainty she felt years ago? When an unlikely (but welcomed by this reader) second chance appears, Petra finds herself en route to Vegas with her childhood BFF to meet, at last, David Cassidy. Because this is a chick-lit novel (destined, maybe, to be a Hollywood “rom-com”), she is also accompanied by older and wiser (and now, successful publisher) Bill. The at-long-last meeting with Cassidy is redemptive in its way. Petra, as you have surely guessed if you’ve been following along here, ends up with Bill. “I Woke Up In Love This Morning,” indeed.

I Don’t Know How She Does It is a very tough act to follow. And unfortunately, I Think I Love You didn’t quite live up to my expectations. The first half moved too slowly (and could probably have been reduced by half), but I enjoyed Pearson’s writing and the bittersweet memories she evoked. The second half of the novel picked up, and while the twists and turns and eventual happy ending are completely predictable, I felt satisfied as I closed the book and focused on my own upcoming date with teen-idol destiny.

My friend and I agreed to meet at the Expo a few hours before the concert, grab dinner and then return for the show. There was bad weather and attendance was light. At one point, as I was waiting, I called my husband to complain. I described the layout of the Expo floor booths:

“Assisted Living, Assisted Living, Assisted Living, Wine-Tasting, Assisted Living …”

“Well,” he replied, “I know where you are.”

My girlfriend and I abandoned the Expo for the hotel bar across the street, but not before winning tickets for the evening’s concert at one of the booths we visited. While we had spent $25 for our “pink section” tickets, these new ones were $100 “silver section” seats! Fate, once again, was inextricably pulling me toward David.

And soon enough (after all, time flies when you’re a “Senior & Boomer”), we were in our upgraded seats. The concert space was odd—stackable chairs in front of a temporary stage in an eerily empty tradeshow hall. The audience was odd, too—mostly mature women and a handful of dates who looked like they were waiting for a root canal instead of a rockstar.

Not me: another fan, a few months earlier in Paris.

The lights dimmed. The crowd went wild.

And I am happy to report that Cassidy didn’t disappoint. He started his set with a jazz version of “C’mon Get Happy.” He sang some Beatles and some Clapton, reminiscing about happier times when he actually hung out with those legends. He’s 62. He’s trim, he’s sexy, he’s so much shorter than I imagined him when I was 12.

After all these years, David Cassidy is the epitome of a trouper. You have to think about what a wild ride he’s been on. He was the single hottest superstar—with the world’s largest fan club—when he was in his early 20s. He fell from grace after an ill-advised attempt to come across as a legitimate musician (and adult) in Rolling Stone magazine, for which he was photographed in the nude by Annie Leibowitz. He eventually became something of a punchline. But through it all, he’s continued to perform. On TV, on Broadway, in Vegas, and recently at the Seniors & Boomers Expo in Boston.

Yet despite the sorry venue, he seemed genuinely happy to be there. He was kind to the fans who stepped forward with albums and pictures and lunchboxes for him to sign. He allowed a little girl (there to relive her mom’s glory days, no doubt) to join him onstage for a discordant duet of “I Think I Love You.” He good-naturedly sang countless insipid Partridge Family songs, and when the evening was over, he sincerely thanked us for allowing him to do what he still loves. He left the stage quickly. We left the concert smiling.

For the record … I am not a “Senior.” I am barely a “Boomer.” But some 40 years later, I am still a David Cassidy fan.