goofy obviously came from a well to do family that had enough money to enroll their child in an institution that taught him how to walk and talk and behave normally. pluto on the other hand came from a less desirable socioeconomic situation and his parents could not afford such education. therefor, pluto never developed the proper motor skills when he was young. and since it is hard to teach an old dog new tricks pluto has yet to aquire such skills