"When he enrolled as a student in the Polytechnic, Einstein developed a know-it-all attitude, and he paid little attention to Minkowski's lectures and skipped many. Minkowski described him as a "lazy dog," and years later, upon the publication of the theory of relativity, he commented, "I really would not have believed him capable of it.""
January 1, 1970
https://en.wikiquote.org/wiki/Hermann_Minkowski