To dream of a locker suggests that there are things about you that no other people know about. Consider and take note of items that can be found inside the locker. For example, to dream of a school locker signify hidden feelings and thirst for knowledge.
To dream that you cannot open a locker or that you forgot the combination means that you are hesitant to take a stand in situations in which you are unsure about the outcome. In dreams where you cannot find your locker, this symbolizes your insecurities.