A more precise formulation is: "what is the role of rote learning in mathematical study?" A purist such as Pólya would say "almost none". You have learned a theorem well when you know it back-to-front, and being able to recite it is extremely shallow in comparison. Actually one outstanding mathematician spoke of the first month of studying a new topic like being rote learning: but that was J. E. Littlewood explaining how he approached getting into a new research area. It of course depends what you're trying to achieve, but I doubt you'd find many good mathematicians really suggesting learning faster than you can expand your understanding. (There may be interesting "cultural differences" in ways of explaining "understanding", though, and these could form the basis of a more reasonable question.)