How does one knowing more than one language help/hinder your creative work?

Honestly, I wouldn’t really know how knowing more than one language could help one’s creative work, as the only other language I know is Indonesian, and even then, I only know very basic information. I can imagine it could help in the translation process sometimes, like if you were to translate a book into another language. Or it could be helpful in terms of educating your readers or bringing in more readers from other cultures. I recently (last semester) read The Swan Book, and I found that having the indigenous words in the book gave it a more authentic feeling. I’ve also recently read a book called The Ingredients of Love, which was originally written in French, but then translated to English. Some of the words in that book were left in French, however, which made for a very interesting read, as I occasionally didn’t know what was being said, but having majority English meant I got the gist of it. That also felt like an authentic book, because having the French words in it made me feel like I was stepping onto the streets of Paris, and I felt like a part of it all, rather than an outsider looking in. In terms of hindering, I can see it being an issue in terms of having words that wouldn’t commonly be known by readers who don’t know the language. Like with the Swan Book, I found that I sometimes got a little bit lost because I thought something was a basket, for instance, when it was actually a boat, which made for some confusing reading. Other than that, I can’t really see a downside to knowing multiple languages. Except if you forgot which language you were speaking and suddenly switched halfway through the book.