i think the whole point of portraying ob1 in tpm was too show the change he must have undergone by the time we get to anh, all though the arrogance is still their it is toned down and it is more about knowing what will happen, perhaps jedi only reach their potential when they are about to die, that could certainly be said of Yoda, ob1 and even vader, they knew they had reached their potential and it was time for then to die.