Mr. Carlson is constantly criticizing his son because M&M is "different", and does not meet up to his expectations. As a parent, Mr. Carlson cannot accept his son for whom he is, and continually carps on him, trying to change his behavior so that it is more in line with what he would like to see.
M&M is inarguably "different", both in the eyes of his parents and of his friends. "Disarming(ly) honest", he is "a hippie in a hood's part of town", "one of those nonviolent types who (practice) what he preach(es)". His friends acknowledge that M&M is a "nice guy, but weird". Unlike his father, however, they are able to accept him, looking upon him as "real absent-minded", but "an awful nice kid even if he (is) a little strange" (Chapter 1).
M&M always wears "an old Army jacket that (is) too big for him", and goes barefoot until "his father (gets) fed up with it", at which point he gets a pair of moccasins (Chapter 1). M&M wears his hair long, which, as is the case with so many youths in the sixties and early seventies, is looked upon by his father as a sign of rebellion, and irritates him to no end. M&M is also "flunking math and gym", traditionally considered "manly" subjects. Overlooking the fact that his son excels in English, Mr. Carlson cannot get over the idea that M&M can be inept enough to fail gym especially. He tells Bryon disgustedly, "How anyone can flunk gym is beyond me" (Chapter 3).