I cry at just about anything. I was always a crier but once I had kids, I'm about 10,000 times worse.
It's to the point that if I'm NOT crying about a situation, that makes my DD way more nervous than if I'm tearing up -- it's more of a "something isn't right, Mom's NOT crying!"
A lot of it has to do with life experiences too. For example, Amazing Grace used to never have an affect on me but as I have gotten older, attended more funerals and it seems every single person has that song sang at their funerals -- I can no longer listen to it without just practically bawling. I can not stand it being sung in church anymore, I practically have to leave the minute I hear the first note now. It has a negative association now.
Same thing with movies that would not have affected me before I had kids in the same manner it does now. I bet some of the movies I bawl through if I saw them 15 years ago, I might get misty eyed or something but not really crying like I would now.