You Taught Me That

Generally, You Taught Me That is a Stock Phrase directed at a mentor. The pupil is exhibiting, and thankful for, a skill or a value that the mentor taught him, and wants the mentor to be proud of him.

In a more dramatic use, You Taught Me That is directed at a former mentor, in a situation where the mentor and the pupil find themselves on opposing sides. It could mean one of three things:
 * 1) The student defeats the mentor using a trick that the mentor had taught him.
 * 2) The student is sticking to the values that the mentor had taught him, before the mentor's Face Heel Turn. In this case, the mentor is a Broken Pedestal.
 * 3) The mentor had been a bad example to the student, usually unintentionally, since the mentor's actions didn't seem to live up to his words. This is what prompted the student's Face Heel Turn, and he is currently exhibiting the same flawed behaviour that his mentor regrets. Expect a lot of guilt on the mentor's part.

Advertising

 * An anti-drug PSA which ran in the early 2000s featured a father confronting his son over a pot stash and demanding to know where he learned to do drugs. The son defiantly shouts, "From you!  I learned it from you!" and the PSA is revealed to lecturing parents about their own drug usage as well as warning them of their children's possible use.

Film

 * An odd variation in that the "mentor" is consistently villainous: in the film Harry Potter and the Order of the Phoenix (as in the book), Professor Umbridge makes Harry magically carve the words "I must not tell lies" on the back of his hand as a punishment for telling a Cassandra Truth (that Voldemort has returned). Towards the end, he and Hermione have lured Umbridge to a centaur herd, and when Umbridge pleas for Harry to tell the centaurs she means them no harm, he replies "I'm sorry, Professor, but I must not tell lies", while holding up the scarred hand.
 * Harry does it again in the seventh film.

Literature

 * In Mort, an Evil Vizier has a plan to poison his emperor but is outmaneuvered by the emperor and has to eat the poison himself. As he's dying he compliments the Emperor on what he's done and the Emperor says "I had a great teacher."