After watching every episode of Diff'rent Strokes, one thing I observed was Mr. D's relationship with Arnold and Willis from the first season all the way to the last. During the first couple of seasons he really cared for Arnold and Willis. He defended them from racism and bent over backwards for them. He loved them. The were his, "sons". Now when that brat Sam showed up, Mr. D only cared about him and Maggie and seem to stopped caring for Arnold and Willis. It was all about Sam and Maggie. That bed wetting episode was the real backbreaker there. If anyone followed DS through the series' run will know exactly what I'm talking about.