I realized my assignment went through an originality checker, which I guess is safer than calling it a plagiarism checker.
Still felt odd that it flagged a quote I used from the source book, in the section asking for a quotation. I would've thought it'd at least disregard things between quotation marks.
What's even dumber is that it flagged a single instance of the word "the", just the word not the sentence it was in. I don't know why, but I guess that specific "the" was unoriginal.