When important events happen, we can divide our lives into two parts: the “before” and the “after.” There’s life before marriage and after marriage, and there’s life before and after kids. There’s our time as a child, and our time as an adult. While we share many of these milestones with others, there are some that we face on our own.

For me, there’s a huge, canyon-shaped dividing line in my life. There’s my life before being diagnosed with metastatic breast cancer (MBC), and my life after. Unfortunately, there isn’t a cure for MBC. Once a woman gives birth, she’ll always remain a mother, just like once you’re diagnosed with MBC, it remains with you.

Here’s what shifted in my life after my diagnosis, and what I learned in the process.

Before I was diagnosed with MBC, I thought of death as something that would happen in the distant future. It was on my radar, as it is on everybody’s, but it was vague and far away. After a diagnosis of MBC, death becomes immediate, powerful, and must be managed swiftly. An advance directive and will were on my to-do list for some time later on in life, but following my diagnosis, I finished them shortly after.

I used to look forward to things like anniversaries, grandchildren, and weddings without any urgency. They would come in due time. But after my diagnosis, there was always the thought that I wouldn’t be around for the next event, or even the next Christmas. I stopped subscribing to magazines and buying clothes off-season. Who knew if I would need them?

Before cancer invaded my liver and lungs, I took my health for granted. Doctor’s appointments were a yearly annoyance. Not only do I see two doctors monthly, get chemo regularly, and practically drive to the infusion center in my sleep now, but I also know the names of the nuclear scanning tech’s children.

Prior to MBC, I was a normal working adult, feeling useful in a job that I loved. I was happy to get a paycheck and talk to people daily. Now, there are many days that I’m home, fatigued, in pain, on medication, and unable to work.

MBC hit my life like a tornado, stirring everything up. Then, the dust settled. You don’t know what will happen at first; you think nothing will ever be normal again. But what you find is that the wind has whisked things of unimportance away, leaving the world clean and shining bright.

What’s left after the shakeup are people who truly love me no matter how tired I am. My family’s smiles, the wag of my dog’s tail, a little hummingbird sipping from a flower — those things have taken on the importance that they should’ve had all along. Because in those things, you find peace.

It’s trite to say that you learn to live one day at a time, and yet it’s true. My world is simpler and calmer in many ways. It has become easier to appreciate all the things that would have simply been background noise in the past.

Before MBC, I felt like everybody else. I was busy, working, driving, purchasing, and distant from the idea that this world could end. I was not paying attention. Now, I realize that when time is short, those little moments of beauty that are so easy to bypass are the moments that really count.

I used to go through days without really thinking about my life and what could happen. But after MBC? I’ve never been happier.

Ann Silberman is living with stage 4 breast cancer and is the author of Breast Cancer? But Doctor … I Hate Pink!, which was named one of our best metastatic breast cancer blogs. Connect with her on Facebook or Tweet her @ButDocIHatePink.