At that moment I realized that fundamentally, these are not my people. I liked the work. But I was never going to like it enough to blow a weekend doing more of it for free. Which meant that I was never going to be as good at that job as the guys around me.
I actually think some portion of this is strongly culturally determined. Women focus on the private stuff, and I don't think it is just because our brains are full of estrogen. I think a large share of this is culturally/experientially derived.
The guy who built the neural network? That may have been his means to deal with a failed romance. He just didn't say that because his love life is not the business of his office mates. This is a distinction I think men are taught to make more than women: These people you work with? They aren't your friends, your BFF, or your soul mates. These are just people you WORK with and if you bond with them, you need to bond over the WORK.
At least, that's my current working hypothesis.