In how many sittings can you watch a movie of 120 minutes?

I have a pretty hard time with even finishing movies. The pacing of such short stories is just incredibly awkward, and it's difficult to be taken in by the plot when you know it's going to be over that soon. There seems to be a very limited scope of stories that can actually be told well in film, and I would say that scope is exceeded far more often than it's honored.