hard when things go badly for them. At the end of the episode, Cox thanks J.D. — and, atypically, calls him by his real name — for helping him forgive himself and get on with his life. After Cox is promoted to Chief of Medicine in season 8, he and J.D. are often at odds over hospital matters, mirroring Cox's relationship with the former chief, Dr. Bob Kelso (Ken Jenkins), in earlier seasons. Kelso advises J.D. that he is the one who will have to press for hospital matters if they're important enough, even if it means fighting Cox to do it. On J.D.'s last day at Sacred Heart, Cox finally admits that J.D. is an exceptional physician, an exceptional person, and a friend — albeit only when he thinks J.D. isn't around to hear it. J.D. is also engaged in a constant battle with the Janitor (Neil Flynn) from the very first episode. The Janitor is trying to open a jammed door when J.D. suggests there may be a penny stuck in it. When it turns out that there is a penny stuck in the door, the Janitor vows revenge. Throughout the series, the Janitor frequently plays tricks and pranks on J.D. In the eighth-season finale, it is revealed that J.D. did accidentally put the penny in the door. The Janitor saw him drop the penny, but because he never admitted it, decided that J.D. had failed a "test of character," thus igniting their feud. J.D. leaves Sacred Heart for a job at another hospital in order to be closer to his son, Sam. In season 9, J.D. becomes a visiting professor at Winston University, a medical school built on the old site of Sacred Heart, which has been torn down. He forms a bond with the series' new main character, Lucy Bennett (Kerry Bishé), whom he counsels through the rigours of life as a doctor. After a few months, however, he tells her that he eventually plans to move on, and that she must find a new mentor before he leaves. Finally, he leaves his teaching position and steps back from mentoring Lucy, determined that she must learn to function on her own. Friends He often spends time with Chris Turk (Donald Faison), his best friend and surrogate brother, whom he first met when they were roommates at the College of William and Mary in Williamsburg, Virginia. The