I was an infant when my mom began to worry about the two words we would come to dread the most: pulmonary embolism. As she researched my diagnosis, Klippel-Trenaunay syndrome (KTS), she noticed those two words often appeared in the literature. “Will we need to watch for blood clots?” my mom asked my doctors in Boston and Dallas. These specialists, some of whom were known for treating KTS and would later develop CLOVES syndrome, said no. At the time, they thought a pulmonary embolism was only a dreaded complication for those with KTS in their legs. I was 11 when I proved the specialists wrong. After a few days in the hospital for uncontrollable hand pain, I began wheezing. The doctors worked through a long list of potential causes, checking for complications like asthma and pneumonia. But as my 02 sats continued to drop, one brave doctor finally suggested the cause that everyone else dismissed. “What if it’s a pulmonary embolism?” he asked. At the time, the suggestion seemed ridiculous. Why would I, an 11-year-old with KTS in my upper body, have a pulmonary embolism? The suggestion seemed so unlikely that my insurance company initially denied checking for a PE. But after another week of decreasing 02 sats and pressure in my chest, the brave doctor spoke up again. When my insurance company finally approved the scan, we learned that the unlikely complication was no longer just two dreaded words. It was now part of my medical history. I was 17 when I had yet another pulmonary embolism. I’ll never forget that nightmarish day, a day filled with dread and distress. A cacophony of wheezing accompanied me as I stepped through the ER doors. “My daughter can’t breathe and may have a pulmonary embolism,” my mom explained to the women sitting at the front desk. “She’s been off of her blood thinner for a couple of weeks.” I’ll never forget what happened next. I’m sure you’re hoping that the women sprung into action, hooking me up to a blood pressure cuff or checking my 02 sats. But that isn’t what happened. Instead, one of the women scoffed in disbelief. At the time, a pulmonary embolism seemed laughable to the woman. “Why would she be on blood thinner?” the woman begrudgingly asked, as if she had already dismissed this “unlikely” complication. My mom quickly and irritably replied, “Because she has a history of a pulmonary embolism!” Just a few hours later, the “unlikely” cause was confirmed. Those two dreaded words were once again inscribed into my medical history. I’m 25 now, and my medical history continues to tell the story of a rare disease patient enduring the unforeseen and unlikely. This story is ever-evolving, yet it also contains repeated themes, themes like those two dreaded words. But it isn’t those two words that really stand out to me today. No, it’s the three little words I used again and again as I shared my story with you: at the time. On Rare Disease Day, it’s those three little words I’m calling our attention to. Those three little words — at the time — allude to progress. They prompt us to recognize that something has shifted, something is no longer as it once was. Those three little words not only set the scene for stories of where we’ve been, but they also call us to celebrate how far we’ve come since. They lead us to remember what it took to get to where we are now. For myself and many other rare disease patients, we’ve watched doctors learn to manage our symptoms through trial and error. We’ve watched researchers make progress in identifying the genetic mutations that can cause these rare diseases. We’ve watched specialists creatively think outside of the box as they’ve journeyed with us through tragedy and triumph. Some of us have even watched our diagnoses shift as new syndromes, such as CLOVES syndrome, have been described. And many of us have not only watched research development take place, but we’ve participated in the very research that has allowed us to say, “At the time we thought… but now we know…” Rare Disease Day gives us a unique opportunity to both celebrate and learn. This day inspires us to honor how far the rare disease community has come; however, it also reminds us that there is still substantial work to do. Whether you’re a patient, a doctor or a friend to someone in either group, there’s work you can do as well. On Rare Disease Day, you, too, can join in the celebration, commemorating the progress that has been made. Nevertheless, I want to also challenge you to learn about where we’ve been and how far we still have to go. Read diverse perspectives. Hear the true stories that spring from someone’s challenging medical history. Listen to a patient navigating the “unlikely.” Ask or research how you can help raise awareness. Amplify the voices and works of those with rare diseases. Join us as we not only celebrate how far we’ve come but also remember what it took to get here, to reach those monumental moments where we could finally say, “But now we know…” Follow this journey on Growing in the Groaning.