For those of you still unsure about your type, watch these videos and stop asking the same stupid questions (like I used to do). The first video is mainly about the differences between Ni and Ne, but it is useful in general for quelling any doubts about MBTI theory itself, and you can find many extremely insightful videos in the 'related videos' section, or on this user's channel. The second video is about the shadow functions and why we need to avoid them.
Also, side-note: the person narrating these videos is an INTJ, and the way he talks - I would argue - is almost definitive of the type. A very good baseline, if you are unsure about how an INTJ sounds in person. I myself talk the same way.
EDIT: Yes I am fucking aware that I typed Ni and Ni in the thread title. Goddamn it, PerC won't let me fix it.