[yifanl]

> people who do things like focus all their energy on the Jacobian conjecture ... Most crash out never finishing their doctorates (because these problems are too hard and working on them does not provide what it takes to survive professionally).

In Zhang's case, I believe his doctoral thesis actually proved the Jacobian conjecture... but his thesis was relying on an incorrect result given by his advisor's own paper (presumably at the guidance of his advisor).