I would call that the "Serge Lang in the next office moment": when I was a postdoc at Yale, my office was next to his. As I was working on my first significant paper, I got stuck on a commutative algebra lemma. After wasting weeks, I knocked on Serge's door and asked him. In 1 minute or so, he explained why the lemma was trivial. The paper ended up in Inventiones and this got me my CNRS permanent job. When I think about how LLMs will change mathematical careers, I keep thinking about this moment.