I've had a problem with crying ever since the third grade when I had to learn "Puff the Magic Dragon." I could never sing it without crying, which wasn't good back then if you're a boy.
I still have a problem with it, despite Peter, Paul and Mary adding a happy ending to it.
It is definitely not an estrogen thing with me. I'd say that it was more empathy and seeing the whole picture. (Poor Puff, left without a friend...)
It has gotten worse over the years, bad enough that I have problems watching some movies and reading parts of some books. Even some of the happy endings can send me on a crying jag.
In some situations, when doing recreational creative writing, I can set myself off. It makes for interesting writing, since I tend to do first drafts long hand, on a clipboard.
(I'm tearing up right now, just before I have to pack up and head home on the bus. SIGH.)