My Spanish teacher from last year told me that "me gusta" and "a mí me gusta" mean the same thing: I like. However, "me gusta" is a more simple way to say it. As an example, she told us that "I'm" is the same thing as saying "I am," but it's more simple. Therefore, it's the same with "me gusta" and "a mí me gusta."
However, this year, my new Spanish teacher tends to use "a mí me gusta" a lot, and I believe she thinks that "me gusta" is wrong, or at least "a mí me gusta" is a better way to say "I like."
Who's correct? Are they really the same thing?