https://hub.jhu.edu/2019/11/07/joel-spruck-mathematics-cartan-hadamard-manifolds-proof-science/

Johns Hopkins mathematician Joel Spruck and a former student recently succeeded in proving a long-standing conjecture about the area of negatively curved spaces, such as flower petals or coral reefs, a yearslong endeavor full of unexpected hurdles and sleepless nights. "This was quite emotionally difficult," Spruck says. "We died a thousand times and then lived. You have the feeling that the gods saved you somehow."