It's rather hard to explain: mica is an odd adverb. It is usually used to strengthen a negation (such as by no means or absolutely not): * Non è mica vero! — It's absolutely not true! * Non sono mica un incompetente! read more
Since I live in the US and I speak Italian with mostly family and we actually speak more dialect than stand Italian . The word can be used when trying to make a point in a nonchalant demeanor such as “"non mi interessa , mica e’ Mia “ or “mica la devo usa per sempre “. read more