...she is Not Nice Enough to the man she's going to marry in the morning. Lovable, kind Rory, who adores her. Sadly, she doesn't seem to return his feelings with the same fervor (except when he dies).
Which happens, in life (I mean the not adoring someone who adores you part, rather than the being sucked into a crack in the universe).
Anyway, I've had a thinky thought. Amy got engaged to Rory most likely because he asked, several times, and she finally said yes because all her friends and distant relatives thought it was a good idea, and she even managed to talk herself into it - even though on some level she didn't quite believe it until here it was the night before and she's got a ring and a white dress...
...and then an alien shows up to whisk her off on Adventures.
But then the Doctor got it into his head that she really absolutely should get married to Rory, the fate of the Universe depends on it, so whisked him
off for Adventures too. Which got Rory killed and then erased from history.
I predict that in the finale, Rory will get undeaded, the wedding will take place on time, except...
...at the altar, Amy will tell him he's her best friend in the world, but she can't marry him and she's very very sorry she didn't say this before.
Because there is, as many have observed, no chemistry between Amy and Rory. Perhaps there was never meant to be chemistry, because Amy/Rory was never meant to be.