Yesterday I learned that my friend, Sandy, had died.

She was older than I was and far less accomplished than most. In fact, she had spent her seven decades as one whom society used to describe as “mentally retarded.” She had no advanced degrees, no career, no fame or fortune — all those descriptors we add to obituaries that make us believe that a life ending had been worth living in the first place.

Sandy had none of that. Yet she was my friend, and like only a handful of other people in my life, she had an enormous impact on me because her solitary expertise was something that I was not very good at.

Friendship.

As the eldest of my siblings, I was the most restricted by my parents. It was a mixed blessing. As an introvert, I didn’t especially mind, but — in life’s rearview mirror — I realize how much those restrictions denied me the opportunity to develop close relationships. I’m sure my parents didn’t realize this; my mother in particular who was herself an introvert.

I did have friends, especially when I enrolled in college, but most of them I held at arms length. I rarely, if ever, let anyone get close to me.

After college, another friend — who made it her mission to befriend me — taught me an extremely valuable lesson: To have a close friend, one had to be a close friend. For me it was a novel discovery, one I took to heart. One reinforced by my friend, Sandy.

I first knew Sandy through my church and through her mother, who cared for her daughter for almost 60 years. Her mother arranged the flowers for my wedding and for our church. Sandy always referred to herself as Sandra, but I always called her Sandy. I don’t know why.

Long ago, Sandy befriended me.

Every time I saw her, she would reference our high school days. I was the editor of the newspaper; she was enrolled in special education courses. I didn’t know her well then, yet that was her frame of reference. She frequently perused her high school yearbooks, looking at the faces of all the people who were her friends. There were many; many who never even knew it. They were Sandy’s friends nonetheless.

When I moved back to the city where we both grew up, she got my phone number and from that time on, called me regularly. I was one of many blessed with her short but friendly phone calls. Often she would ask if I had heard from this person or that, or if I knew that so and so was ill, or that so and so had died. For a woman with limited mental capacity she had an enormous capacity for friendship.

Every year I took her a birthday present. It was easy to remember because she shared the date with my eldest son. Often I missed getting there on the exact day and would have to tell her, yes, I’m coming but not sure when. I hoped it was always a nice surprise for her when I showed up unannounced with her birthday gifts in hand, sometimes weeks or months after the event.

But surprise or not, I know that I always left her presence uplifted. She put my own life in perspective and made me think deeply about the value of human relationships — something I was never especially good at. She helped me understand that this is where life occurs; it is not in the accomplishments, the accolades, or the degrees that we rack up.

It is in the people we touch.

Sandy lost her father years ago, but when her mother died in 2004, she lost her dearest friend and caretaker. She was heartbroken at their temporary separation. For the rest of her life, with the deep and genuine emotion that people like Sandy are blessed with,  she never let go of the acute pain of losing her mother. It was as intense for her after 15 years as it had been the day her mother passed. How many times she said to me, “I miss my Mom.” When I heard that Sandy had died, my first thought was how happy she would be at their reunion.

I don’t know what Sandy’s obituary will say. It won’t follow the traditional text because she didn’t live a traditional life. But I hope it will say that my dear friend Sandy was a master of friendship.

Because she was. And that was more than enough.