Two Faced?

While on a Google quest to try and work out what happened to Al Pacino's face between the Godfather and the subsequent Godfather movies, I received this awesome little ad:





LOLOL!!!



Incidentally, am I the only person that wonders what the hell happened between Godfather 1 and 2?!





He was such a smooth skinned guy and then BOOM (no pun intended), gaunt-faced Al. Did he have a meth addiction I am unaware of?



Inquiring minds need to know...