Sheryl Sandberg, the COO of Facebook and author of 'Lean In,' delivered the commencement address at Virginia Tech in May 2017 — two years and eleven days after the sudden death of her husband Dave Goldberg. The speech was deeply personal, built around the concept of resilience that Sandberg had been studying with psychologist Adam Grant, research that would become their book 'Option B.' This quote captured the single most important insight from that research: resilience is not a fixed trait that some people have and others don't. It's a capacity that can be developed, strengthened, and grown — like a muscle. The metaphor was deliberately physical and actionable, pushing back against the fatalistic belief that some people are simply 'tougher' than others. Sandberg's own experience of rebuilding her life after devastating loss was living proof.