I also want to point out that Amos' story was eerily similar to Daniel Komen's- immediate success (Amos only began training in 2009) followed by ego, complacency, and laziness.
From 2013:
This was his first championship title but since taking up running as a 15-year-old in 2009 progress has been swift – helped, he says, by watching Rudisha’s races on YouTube. He was rewarded for his silver medal at London with six cows, but last year he suffered with a thigh strain and a potentially more pernicious problem: fame.
His elder sister Francinah warned he was becoming hostile to his family and was bragging that he could win races without training. He launched into a music career, calling himself DJ Zoroski. He crashed his car. Some feared he was losing his way. But watching men he knew he could beat win medals at the world championships last year from his room – an experienced he described as “painful” – reignited the fires. And how.
Amos has also been injured quite a bit. However, I think he still has WR potential, and given Vasquez continues to rabbit races, Amos could potentially challenge it in a year or so.