I broadly like the idea of "slicing up reality differently". Usually when this it comes up the focus is on grammar, but I think this explains the relative ease

I broadly like the idea of "slicing up reality differently". Usually when this it comes up the focus is on grammar, but I think this explains the relative ease/difficulty of learning close/distant languages quite well. You can argue about whether grammar or vocabulary acquisition is more difficult but it's certainly true that there's just more of the latter. One way I look at this to pick a word with many quite different meanings. "Set" can mean a group of things or something to turn hard (like a jelly) along with plenty of other things. Since European languages tend to share ancestors you aren't surprised that these multiple distinct meanings are shared. But with distance languages you have to learn a completely different word for each particular meaning. In fact, I'm sometimes surprised when two different meanings line up between English and Japanese, as I'm so used to them being completely separate.