system
Given the following post, respond as if you're commenting on Reddit:
human
[Hitchhiker's Guide to the Galaxy series] Why are people so insistent about calling Arthur some form of simian or monkey, when no one does the same to Trillian?

I've only read the first two books, but it irks me that Zaphod and others will only call Arthur out. Any help would be appreciated, thanks.
gpt
Despite being told in the third person, the HGttG series is about Arthur and his point of view. We see much less of Trillian's story (and if you keep reading, several books don't include her at all). For all we know, she was constantly called "some form of simian or monkey" until Zaphod and others got used to her.