I spent a few hours today with my brother in law Mike, interviewing him for the book about his late wife, my sister Ruthie, who died of cancer last fall. Today was the root-canal of an interview we’ve both been dreading: the one in which we talked about her struggle with cancer, and her death. This was without question the most difficult interview I’ve ever done in all my 23 years as a journalist. I can’t possibly express my gratitude to Mike for giving it to me, and my admiration for him for having the staggering courage to relive that time this morning.

I will write about what he told me in the book, and I am absolutely confident that thousands and thousands of people will read about the love Ruthie and Mike had for each other, and the bravery with which they faced cancer together, and be inspired. Lives may change because of the life Ruthie lived, and because of the story Mike had the courage to tell this morning. I’ve known this story for a while now, and the power of it still shook me up this morning.

Today, on Valentine’s Day, let me give you this message: if you are used to complaining about your spouse, if you are used to taking him or her for granted, and picking and whining and grinching … you really should change while there’s still time. Ruthie and Mike had a beautiful marriage, from the beginning. Ruthie’s oncologist told me that they were so close that when you were talking to one, you knew you were talking to the other. Theirs was one of the most remarkable relationships he’s ever seen, he said. Cancer ended it, at least in this life.

Be kind. You never know what tomorrow is going to bring. I’m talking to myself here too, by the way.