I was lying in bed, watching something with my son when a chat message popped up on screen. It was my dear friend, Narin, whom I haven’t seen in years but remain in contact with (thanks to the wonders of social media).

“Did you hear that Dave died?” she had written. “I just read it in our college alumni magazine. I am so shocked.”

At first I wasn’t sure whom she was referring to, but then she clarified, “David Thomas*… he’s dead.”

As I realized who she meant, I was overwhelmed with sadness. Indeed, had I not already been lying down, I think I might have buckled. I Googled him and  located his online obituary. There was no picture, but I learned he had success in business, was married, and had kids.

As I read it, my thoughts went to my days as an undergraduate. I had left my native island home in the South Pacific to study in upstate New York. As a freshman, I was placed in a suite of upperclassmen. Dave had been in the adjoining suite and although I cannot remember the details of our first conversation, I do recall we discovered things in common, like how we shared the same birthday and that we were both only sons (he has five sisters while I have four). Despite being older than me, we found it easy to talk to each other and almost immediately, we hit it off and during my first year away from home, he showed me around campus, introduced me to his friends and to his fraternity. I ended up pledging that fraternity, and Dave became my “formal” big brother.

I thought we would remain in touch always, but as often happens, when he graduated (two years before me), our lives went in different directions. I went on to medical school and lost contact with him. Despite the passing of years, though, I would think about him every so often–wondering how he was doing and mostly looking forward to a future reunion … someday. Surely, time was on our side.

Learning of his death has been a shock for me, primarily because it was so unexpected — like having the rug pulled out from under you. It has made me cognizant (yet again) of how precious time is — that one never knows how long one has on this earth.

It also made me think about the discussions I have with my patients, particularly those where I have to discuss the difficult and scary issues of cancer recurrence or metastases, when cure is no longer a possibility. I often encourage them not to dwell on the “incurableness” of cancer, but rather to focus on the fact that they are alive today, and very much so.

“Afterall,” I’d say, “one can be hit by a car or drop dead of a heart attack in an instant. It would be over just like that.”

I know for some patients these sentiments do help alleviate worry; but for others, they seem to ring hollow.

“What do you know? You don’t have cancer.”

It occurs to me that I approach these discussions with a certain level of detachment, as if they do not apply to me, as if I am immune to death. Then something like this happens, and I realize that I am no more immortal than my own patients.

Ultimately, Dave’s death has made me pay attention to what I’ve been saying, to heed the very advice I have given to so many others. I must live fully and not delay doing the things that I want to do, such as reaching out to those people from my past that I miss. In the end, life is a gift and none of us know how long we will get to enjoy it.

It is heartbreaking for me to realize I will never have that reunion with Dave. That I will not have the chance to thank him for being such a great big brother all those years ago, to tell him he made a lasting impression on me, and that he was never far from my thoughts.

But for those he loved and left behind, I hope they know that he mattered. This world is a better place because of him, and I am certain his influence was shared by more people than just me.

Rest in peace my friend.  May the journey beyond be peaceful, and I hope I get to see you on the other side.

* Name has been changed.

Don S. Dizon is an oncologist who blogs at ASCO Connection, where this post originally appeared.