Primary care doctors like me often rely on “the tincture of time”—a period of observation and waiting as a key treatment. It’s not always simple for patients, especially when imaging might reveal back pain or when a child’s symptoms persist despite negative tests. While urgent care is sometimes necessary, most cases benefit from a slower, data-driven approach.
I’ve experienced this personally. My late husband Paul’s back pain initially led to terminal cancer, highlighting how time can sometimes bring unexpected tragedies. Yet, more often, waiting allows symptoms to resolve, clarity to emerge, and children to recover.
A physician myself, I’ve reflected on Paul’s insights about balancing medical decisions and life’s uncertainties. As a general internist, I’ve learned when to investigate further and when to trust a patient’s instincts. Unnecessary tests can cause harm, so we often prioritize cautious observation, leveraging both clinical intuition and the patient’s lived experience.
After Paul’s passing in 2016, our daughter Cady has become another chapter in this journey. When I see her—wide-eyed and familiar in her curiosity—I’m reminded that parenting requires similar patience. Every choice, from education to discipline, is a calculated guess. Yet, I focus on being present, offering guidance while trusting time and growth to shape her future.
Cady hasn’t engaged with Paul’s memoir yet, but it remains a symbol of his legacy. I wonder if she will read it in her teens or if it will sit on our shelves as a reminder. Her journey is hers to navigate, and I’ll remain a steady presence, guided by careful planning and the understanding that some answers will reveal themselves with time.
Lucy Kalanithi is a clinical associate professor of medicine at Stanford University. She contributed the epilogue to When Breath Becomes Air, her late husband’s memoir. She resides in the Bay Area with her family, where her sister Joanna frequently visits and her niece challenges her to Block Blast.

