Yeah; for me there were countless times where I would send in an assignment, and it "wouldn't get through", so on Monday my mom would wake me up to words such as "Get up and complete the schoolwork you didn't do last week."
'n once I had to write about why I shouldn't plagiarize because I had - at the time - been saying words in a different way, because of the people I was hanging with. Colour instead of color, for example. So an essay I wrote was "fairly similar" to something else apparently on the internet. -_-;