This isn't quite fair - it's not so much that it's horrible to say, but that it's easy to say when you aren't emotionally invested in the relationship. Nobody would criticize someone who jumped ship if this episode happened on a first okcupid date. There's a reason this subject didn't come up in their conversation for eight months, and I don't blame her for that.
On the other hand, I know a guy who was about to break up with girl when she got a cancer diagnosis. He stayed with her for years, miserable, because he didn't want to be that schmuck.
Relationships are complex. It's poor form to criticize someone who stays, but also poor form to criticize someone who leaves - there's a lot more going on than just one issue, even if it is a big one.
can't reply to OP.
I'm amazed by the lack of humanity in some of the comments that came up.
I can understand if someone is too weak to handle it or the disease is too disturbing that it makes a relationship impossible, but this looks like people talking about other persons as products.
I wonder what will the OP do when in a relationship he ever has an accident or something that turns him into poor relationship material? would he break up with her. would he try to keep her as a girlfriend and think she was a sucker if she didn't leave?
You're not showing "humanity" if you stick with someone in a new relationship upon discovering a mental disorder. It's a personal choice; someone making a different choice doesn't lack humanity.
And once children are involved, it is not just about you. Plus, you're bringing that person not only into your life but into your family.
Here is something: what if your feelings change because of this? Should you stay, just for the sake of demonstrating your humanity to the world?
Oh, right, it's okay to break up because of changing feelings, because those are human.
My life experience tells me that it's not worth meeting broken people and supporting them, fixing them and so on.
It's a good way to make yourself miserable. If you have a pattern of doing this, it says something about you. Maybe you don't think you deserve better or something, or you need to feel that someone depends on you and needs your support.
Latching on to needy people and supporting them doesn't mean that you're good relationship material in any objective sense; it's just your self-image of what you think makes you "good" is in a relationship.
Your comment's emphasis of the "3 hours a year" tells the reader that you have a "deal-breaker threshold" with respect to this, which is tied to the value of the "number of hours per year" parameter.
(But of course, your threshold is at the optimal sweet spot value, between "fool" and "inhuman").