One often reads stories along the lines of "I was told I wasn't suited to a career in academia; now I'm a professor at < Big Name University >". At the same time, given the structure of the academic job market, many people who desire an academic job will never get one. I am sure many of us can think of individuals who made big sacrifices in an unsuccessful pursuit of an academic career, despite never really being a competitive candidate. Equally, we can probably also think of people who succeeded, against our prior expectations.
Given all the above, what should an advisor do/say when confronted with an early career researcher (graduating PhD student/junior postdoc) whose career goals appear incompatible with their current trajectory? How do you support and encourage your advisee, while also being realistic?