They say (I don't know who "They" is, but a lot of quotes sure do come from "They") that imitation is the sincerest form of flattery.
It starts young. A sibling repeating everything the other says until the other one gets fed up and yells "Muuummmmm.......She's copying me". Then the cheeky sibling says all so quiet, but just loud enough for the other, and mum, to overhear "She's copying me". And then it goes on...."what?" "what?", "Stop it" Stop It"....you get the idea.
Then it's folders up between you and your desk mate so they can't see your work. Somehow, magically they still can see and copy your answers, and end up with a better mark. After all your hard work.
Then in high school, you are asked to complete an assignment, with factual information. I for one remember sitting there with the encyclopaedia Britannica (These days I think you just copy and paste from Google) and a Thesaurus trying to replace some of the words so it looked like my own work. Then, when there was blatant copying, just sticking in the good old footnote. Thinking back, I am sure the teachers would have had a good giggle at some of the words plucked from the Thesaurus and inserted into year 9 homework.