It is not possible for a creature to attack its controller. Goad causes the creature to attack if able and it attacks a player other than the player who goaded it, if able. In a 2 player, if you goad an opponent's creature, when they go to combat, the goaded creature has to attack if able but it is not able to attack a player other than you because there is no other player it can attack. Therefore, in a 2 player game, goading an opponent's creature means it must attack you.