Probably the greatest ever decathlete, Ashton Eaton, retired way early because he thought he had no more challenges in the sport. Athing Mu might just retire early because she puts too much pressure on herself to lose in her event, in which she was finally pushed really hard for the gold last year, when she wasn't at full strength, and had to essentially cut off Hodgkinson to win it. It is a damn shame she hates to race because she has shown the potential to win golds at 400 and 800, and even to potentially medal in the 1500m with some more specific training. That such a talent as we have perhaps never seen before would lose the desire for it is surprising.