In early December, about a month ago, I had the to perform one of the hardest tasks I’ve ever faced as a leader, letting my team know that a colleague had passed away. She was a friend to us all, and the glue that held the team together; telling them that she was gone was, without question, the hardest thing I’ve had to do in a work setting.

What made this so hard was not just what I was telling them, but my own feelings for her as a friend, and the opportunity I had missed. During her final weeks fighting an extremely aggressive cancer, I gave her space and communicated through a mutual friend to minimize the strain she faced. What I wasn’t ready for was the call letting me know I wouldn’t get to talk to her again.

Shortly before starting this post, I learned that the younger of my two sisters has passed away. She held the details and extent of her illness as a secret to most of the family; there was no chance to prepare, no opening to talk, just a call saying she was gone.

The list of people I’ve lost to cancer keeps growing, and while this has led to more than one regret for things left unsaid, this one is just crushing. The loss of a close family member is always hard, the loss of a family member that should have been closer is even worse.

My sister was an amazingly kind and caring person. She also made more than her fair share of bad decisions. If her life were turned into a movie, nobody would believe that it was true. She has been through things that few people could survive on their own, and she seemed to have them occur on a regular basis. From brutal assaults by her ex-husband’s drug dealer, to being the only known survivor of a serial killer that left her for dead. The list is long, and never seemed to stop growing.

Much of her life, from being put on a bus with a one-way ticket across the country to fend for herself at 14. Was spent stumbling from one tragedy to the next. I know only some of the story, and what I know would be difficult to believe if I didn’t already know it was true. Having suffered so much, it was truly remarkable that she remained that kind, caring, and loving person that she was.

Around 2008 I made a decision that I now regret deeply, in an effort to protect my own emotional state, I stopped talking to her. There were too many problems, too many tragedies, too many things that needed to be fixed. I tried my best to be a good brother, but eventually it became too much. I stopped responding to her messages, stopped returning her phone calls, I stopped seeing her.

Her life was just too much for me to handle.

Today, as I sit here writing these words, the decision to put myself first seems nothing but cold and selfish. It wasn’t necessary. There were other options. Now, there is no chance to correct that mistake.

I’ll never be able to apologize, I’ll never be able to make up for lost time, I’ll never be able to provide the support or friendship she needed. She went to her death feeling I didn’t care, and for the rest of my life I’ll carry the burden of this mistake.

I assumed there would be a chance to change things, I assumed that at some point we would reconnect and be close again. I assumed I had time to make things right.

It’s too easy to put off to tomorrow, what should have been done yesterday. Tomorrow is never guaranteed, and sooner or later they run out.

If you love someone, if you care about someone, if you appreciate someone, tell them while you can. You never know if there will be another chance.