I think of the interjection "boy" as being some 1930s-1950s movie speak for earnest young people expressing surprise or excitement about something, not office related at all.
My comment was meant as a joke, given the context. I am familiar with these interjections, even as a non-native anglophone. Sorry for the time you took to write a good reply.
It was fun for me to dig in and find out just how long boy as an interjection has been around for (which is, by far, not an obvious thing regardless of whether one speaks English natively or not).
Same goes for trying to think of other nouns which are used as interjections (the Wikipedia article on interjections lists very few, if any, nouns).
So it was fun to think (and write) about.
FWIW, English isn't my first language either — so I hope we both learned something.
By the way, I couldn't find out why or how "boy" came to be used as an interjection — it doesn't readily appear to be a minced oath — like gosh — or a euphemism (like darn). It remains a mystery to me. So familiarity with these interjections doesn't mean there's nothing to discuss or explain :)
(I don't think I'm getting what the joke was even now, but that's beside the point)