All of the Jin Yong protagonists proved to be extraordinary martial arts learners, but was Deun Yu the one learner who surpassed all others? Starting from a background of NO martial arts at the age of twenty, he was able to learn Bak Ming Sun Gung and Ling Bor Mei Bo very quickly and with no guidance. He also understood the concept of 6 Mak Divine Swords after a casual glance.
I don't think we see any other Jin Yong character pick up and grasp advanced new martial arts concepts (especially starting with no previous background) that quickly.