(Presumably, this is because our mental machinery for predicting others' behavior relies far too heavily on our own habits, experiences, ways of thinking, etc.)

I've been thinking about that. I'm not sure what the solution is. Thinking that other's behaviour is unlike our own is very unhelpful, because it doesn't say which bits are unlike our own.

Also people tend to form groups of people like themselves, so there is less data to gather naturally. I'm also not sure fiction helps either, it tends to be unrealistic.