It is "I" not "Me"

I came across something in our book today that made me think back to the 1st grade. My teacher really was a stickler about this and as I read what our book entails, I feel she may be wrong. "My sister and I went to the store" she would always say. "My sister and me" was absolutely wrong. Many of my friends even growing up were taught this. It is really something that these teachers may be wrong. We were taught this because we are supposed to use I, the nominative case form of the first person pronoun, rather than the accusative form, me. According to Emonds (1986), this logic is not really logical. Does this make sense: We went to the store/Jane and we went to the store/Jane and us went to the store?  When we were told that My sister and I, it really does not have enough logic behind it to use it. This cannot be generalized to pronouns other than I. Pronouns show case in English, and prescriptive rules of them depend on the "correct" case in English. These rules are often inconsistent. So the next time we say My sister and me went to the store, it really is not logical to say that it is wrong.