Every once in a while, something unexpected occurs that shakes me to my core — where I question the point of life, ask why we even bother; when in the end, it all just ends.

This time, it happened on a Sunday morning. I woke up in a good enough mood — the sun was shining through my windows, and my cat, Katniss, was purring by my side. I rose from bed, and as has been a recurring habit, picked up my smartphone to see if I had any messages. There was only one — and it was enough to send me reeling.

“I am sorry to tell you that my beloved partner Jane* died last week.”

Jane wasn’t a friend exactly, more of a fond acquaintance. Although I didn’t know her well, I had always liked her. Over the last three years our lives had crossed every summer, as we retreated to the same Cape Cod community. I’d see her walking her dog and it would bring a smile to my face. Indeed, I looked forward seeing her and her partner, Lynn, when summer came.

Last time I saw Jane (which wasn’t that long ago), we exchanged small talk, asked about each other’s lives. She asked about the kids; I had told her they had hoped to ride her paddleboard with her again.

“One of these days, we will have to have her and her partner over,” I had said to my partner later, “I think it would be really nice to get to know them well.”

This email from Lynn telling us that Jane had died became a stark reminder of how uncertain the future is; that there are no guarantees of “some day.” And I just keep thinking, “That’s so unfair.

Jane wasn’t much older than me, had not even looked sick. She was in her prime, so full of life. Although I do not know how she died, it just didn’t matter. She was gone. There was only one word to summarize what I was feeling: grief. That the death of someone I wasn’t very close to could have such a notable effect surprised me.

At her wake, she was dressed in a gold shirt. She was beautiful, as if she was sleeping. As I knelt next to her casket to say a prayer, I gazed upon her face and the song “If I Die Young” by The Band Perry, played in my head:

If I die young, bury me in satin, lay me down on a bed of roses.

Sink me in the river, at dawn.

Send me away with the words of a love song.

I went to Lynn, at a loss for words. We hugged and all that came out was, “I am so sorry.”

Some of the most valuable lessons I have learned as an oncologist have come from those I have cared for; the women and men who have let me in to their lives after cancer unexpectedly entered into theirs. I have learned to cherish life, every experience — sad and happy. I learned not to procrastinate — to do and say what I think needs to be said in the now, not saved for the future. They have lent me the clarity to try and see what is important; that success in life is measured by the smiles, laughter, hugs, and kisses given and received, more so than the money and power and academic appointments that await you professionally.

Yet, although I feel I have become a better person because of oncology, I cannot escape the fact that unexpected events can still impact me. I think it is because, at the end of the day, there is so much not under our control. I cannot promise my children that I will be here to see them blossom into adults and that the world will always be kind to them. Nor can they promise me that they will never get sick.

The truth is that we only have today. So, I will live it and not waste my time wishing for something different than what is right in front of me. I will stop and smell the roses. I will do it for myself, my kids, my partner. And for this instant, I will do it in memory of Jane.

May she rest in peace.

*Names changed to protect privacy.

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