People always say Chase doesn't know how to make things match. He sees the way people look at him. Most of his shirts have at least two too many patterns; his ties make that total add up to four. On his first day, Cuddy comments that at least House doesn't care about his employees looking professional.
His apartment looks like it's been decorated by at least four different people. The couch is soft brown leather; the coffee table is painted orange. The hardwood floor in the living room is covered with four different colored throw rugs.
Chase knows what people would say if he allowed them inside. They're the same words he's heard all his life.
Poor kid. Crazy mum, absent dad. Doesn't know how to live like an adult.
The truth is, he can't make things match because he doesn't know how to piece his life together. Doesn't know how to pick coordinates off a shelf, or buy a matched furniture set, because they don't have any meaning.
So instead he picks the pieces by hand, and by wish, and by the life that's just out of reach. Because even though he can picture himself on the couch with an as-yet faceless woman in his arms, and wearing the latest crazy tie to a bar with a group of friends, nothing ever changes.
In the end, he concludes that he is the one that doesn't match.