Stories are generally told to reinforce someone's existing narrative. If you think someone is an idiot you will tend to tell stories of them looking foolish. If you think someone is brilliant, stories of them looking clever. All humans, if you looked at their sum-total of actions/decisions, could likely be equally well placed in either camp. Which stories are remembered/repeated is probably as much due to chance as desire for historical accuracy. Not many people, when they think of Newton, think of an alchemist.