There is no "you". There is a text stream that is being completed with maximum likelihood. One way to imagine it is that there are a lot of documents that have things like "if you are in a lightning storm, you should ..." And "if you are stuck debugging windows, you should reboot before throwing your computer out the window".
Starting the prompt with "you" instructions evidently helps get the token stream in the right part of the model space to generate output its users (here, the people who programmed copilot) are generally happy with, because there are a lot of training examples that make that "explicitly instructed" kind of text completion somewhat more accurate.
Starting the prompt with "you" instructions evidently helps get the token stream in the right part of the model space to generate output its users (here, the people who programmed copilot) are generally happy with, because there are a lot of training examples that make that "explicitly instructed" kind of text completion somewhat more accurate.