Comment by wbl

BSD is hard to appreciate because it connects a function that only now is known to have the right properties for the expression on the left hand side to a group we know next to nothing about, plus other mysterious factors each of which could be a few months to really understand. Proving the function exists? That went a bit beyond what was needed for Fermat's Last Theorem. Number theory demands breadth as well as depth. So no surprise it's hard to understand.