In 2018, Keller revealed that in January 2014, after going through both his divorce and becoming unemployed, he had become homeless and lived out of his car for roughly ten months (managing to shower at a gym, where he still had a membership). He also said that, for four years, he lacked visitation rights with his children, making him unable to see them, despite living only minutes away from them. In an interview he conducted in the spring of 2014, he stated that he was no longer certain of the whereabouts of three of his Olympic medals. In the same 2014 interview, Keller also said that he had failed to find similar successes in his endeavors after retiring from swimming. He said that he made the mistake of not having the foresight to plan for his post-swimming career, and felt somewhat "bitter" both towards himself and his sport. He expressed regret for having continued swimming for another four years after the 2004 Olympics, saying that he believed, in retrospect, that he should have retired after the 2004 Summer Olympics and gone back to school thereafter.