My undergrad advisor had a similar story. He was working on an old open problem for his dissertation, and his advisor (quite a well-known figure in the field) k

My undergrad advisor had a similar story. He was working on an old open problem for his dissertation, and his advisor (quite a well-known figure in the field) kept giving him ideas. Nothing worked. This went on for 4 years. Then one day he decided to stop listening to others, and just work on his own. Six months later, he had a novel solution, closing the problem. His entire dissertation (including title, abstract, etc.) was 22 pages (single sided, double-spaced).