The Curious Case of Benjamin Button

Me, Cal and Tom went and saw the Curious Case of Benjamin Button the other day and i was pleasantly surprised.
The fact that it actually held my attention the whole time(nearly 3 hours long) was quite amazing.
I am now officially a fan of Brad Pitt, but the one problem with his acting in this movie was that i don't think he showed enough emotion. It didnt go deep enough into that side of it, so instead of being a fantastic movie, it was only great.
I feel the director might have blown it a bit, as storyline's this original don't come round very often, but although it looked good, i kept thinking that it was just a pretty standard way of telling the story.
Even though it was sad, but also humorous, it did not captivate my emotions, just skimming the surface rather, of mild amusement. This was not to say that i did not enjoy it, becuase i definatley did.
But i left thinking what could have been though.
Imagine a plot like that, with a better screenplay, and some powerful acting like Heath Ledger in the Dark Knight, and hey presto! It would have been a 5/5

instead its a 3.5/5