Sounds like Paul Erdős had it figured out... https://www.britannica.com/biography/Paul-Erdos https://www.britannica.com/biography/Paul-Erdos > Erdős would sho

Sounds like Paul Erdős had it figured out... https://www.britannica.com/biography/Paul-Erdos https://www.britannica.com/biography/Paul-Erdos > Erdős would show up—often unannounced—on the doorstep of a fellow mathematician, declare “My brain is open!” and stay as long as his colleague served up interesting mathematical challenges. (More anecdotes here: https://archive.nytimes.com/www.nytimes.com/books/first/h/hoffman-man.html?source=post_page-----f64e1575de29---------------------- https://archive.nytimes.com/www.nytimes.com/books/first/h/ho...)