In comparison to Pope John Paul II meeting with and forgiving the man who shot him, Pope Benedict’s meeting with Susan Maiolo and giving her forgiveness may seem a little odd or at least much less significant.
But something almost no-one has commented upon is the fact that by assaulting the Holy Father, this woman – a Catholic, compared to the Muslim gunman – was, by virtue of her act, under a latae sententiae excommunication according to Canon 1370 (see this rather humourous article on an atheist site):
1370: A person who uses physical force against the Roman Pontiff incurs a latae sententiae excommunication reserved to the Apostolic See
So his personal forgiveness was necessary for the removal of this excommunication. Perhaps physically assaulting him could be seen as one extreme but sure-fire way of getting a personal audience with the Pope! (NOT recommended, BTW! )