I just had a birthday. As usual, I received a handmade card from Beth Catlin, who has been sending me such birthday greetings for more than three decades, even though we’d never met until 2009.

That was the year I decided it was time to finally meet Beth in person. Eager to put a face with her name, I visited her workplace, the C. Wilson Pollock Industrial Training Center.

“Hi, Beth,” I said, shaking her hand hello. “I’m Ronnie. It’s wonderful to finally meet you. Thank you for all the cards.”

She looked at me with brief intensity, then her eyes darted away as she said: “Ronnie. July 3.”

Which is my birthday.

I mentioned the names of several of my many siblings, to whom she also sent annual greetings, and she recited their birthdays, too.

“That’s right,” I said. “You’ve got them all correct.”

She smiled, pleased, and said, “Yeah.”

Beth, now 59, is an autistic savant. Intellectually and developmentally disabled, she lives on a sweet little block in Mechanicsburg, just south of Harrisburg, with her widowed mother, Barb, who is now 88. Her wonderful dad, Don, passed away suddenly seven months after my visit.

But he was alive and vivacious the day we met, eager to talk about the extraordinary mission Beth began some time in 1972: She sends hand-made birthday greetings to every person she has ever met — and to their friends and relatives, whether she has met them or not (Beth’s sister went to school with my own sister; Beth got my name and date of birth from her).

Astonishingly, each of our 5,000-plus names, addresses and birthdays are not listed in a personal address book but are instead permanently encoded in Beth’s brain. The spellings are exact, our birth dates precise. And not one card has ever been returned to her because of a wrong address, said her mother.

“This is her gift,” Barb explained to me back then, while I watched, astonished, as Beth addressed — from memory — more than a dozen cards at the desk where she still keeps her notes, envelopes and stamps. “Hers is a world of word and number association and constant observation, mixed with interrogation.”

Barb and Don realized, when Beth was 3 years old, that something was wrong with their angel-faced toddler, the older of their two daughters, who was not developing the way her baby sister had begun to. Years of intervention helped Beth learn to read, write and speak, though she still has only basic comprehension of the language she uses.

This is her gift. Hers is a world of word and number association and constant observation, mixed with interrogation."

Barb Catlin, whose daughter is an autistic savant

Physically, her gait is slightly unsteady, but it does not impede her daily walks around the neighborhood or from full-time employment at nearby Wilson Pollock, where she has worked for 38 years alongside other adults with disabilities doing assembly work for vendors. The day I visited, she was methodically placing labels upon the handles of rakes that her work group had put together for shipment to area home-improvement stores.

“Beth’s a very conscientious worker,” said Susan Wenning, who was the center’s assistant director for vocational programs at the time. “She’s paid for each piece of work she does, so she likes to stay busy. She likes to see that reflected in the numbers on her weekly paycheck.”

Beth’s obsession with digits is similar to the kind so unforgettably personified by Dustin Hoffman in the movie Rain Man. While her gift is not an uncommon one among “number” savants such as herself, I find it immensely moving that it manifests itself in such a thoughtful way.

How many of us always remember to send birthday greetings to the important people in our lives? Or perhaps have felt a pang of hurt when our own big day has been overlooked by others caught up, as we often are, in the rush of life?

“Some people have told us that Beth’s card is the only birthday greeting they can rely on receiving — or the only one they look forward to opening,” said Don, who described his daughter as “one of the most extraordinary people I’ve ever known.”

Beth’s gift has come at a cost. She has never mastered simple tasks like grocery shopping, household chores, and social relationships, and she hasn’t the capacity to be reasoned with about some simple things, such as where to put a dish towel when she’s finished using it.

She and I are close to the same age, and yet our lives are so different. I have a husband, child, close friends, a job I love, and more reasons than I can count for looking forward with hope and joy to the future. Beth lives moment to moment, moving through life without any apparent emotional connection to any of the things, past or present, that give life obvious meaning to many of us.

And yet she has made it her mission to acknowledge more than 5,000 birthdays every year — an act of stunning intimacy, given Beth’s otherwise lack of intimacy with the world.

In return, hundreds and hundreds of people in her “birthday circle,” as I like to call it, respond in kind, sending Beth cards on her own special day: Sept. 22. Barb said her daughter’s face glows with excitement when the mailbox overflows with so many birthday cards, all of them for her.

“Beth has made so many people happy with her thoughtfulness,” said Barb, as I hugged her goodbye that day, profoundly touched by the family’s pride in her. “This is our reward — and her triumph.”