[garmaine]

By his own report, it was a few months of tackling the problem from various angles until he found the pathway that would eventually bear fruit, and formalizing that and fixing little problems along the way was what the next six years were spent on.

[pas]

He was the lucky one. Many many mathematicians thought they saw a path. And spent years. And it did not lead anywhere/there in the end.

See also the many P = NP proof attempts. (Sure, most of them are complete crackpot garbage, but that doesn't mean serious attempts are not made, and probably more serious attempts are made that then go nowhere so the author doesn't disclose it.)