Most people who do have NPD will never know it, like most of us it's all normal until the day you realize it's not. I believe most will never know that they have a disorder as it just seems of the norm to "us". Then there are some of us who do strive to recognize the negative traits and make a conscious effort to try to manipulate them. I know I have my days of trying to be better and others where I could care less and act in ways I know best. You see the hardest part is that for most of the time I am so comfortable with my ways and continue them. The problem is that these ways have impact on the people close to me as my wactions are great for "me" but really nobody else. (Sorry for all the "ways" used)
If you can recognize negative traits and you are ok with them are they really that bad??
For myself I know things around me are great..... The reality is we make others suffer to achieve these things and because we cannot feel empathy it makes it very difficult for them. To not understand how we cannot feel for them or that we could care less on their wants only to continue with what works for "me". It's so much easier to see a person not able to get out of bed due to depression or able to deal with others. They are hurting like us but can't deal with the world. What makes us so dangerous is our ways to act if everyone is beneath us while actually making others believe this. We have our coping mechanisms and unfortunately the ones around us pay the price for our "coping skills". Sweep people off of their feet only to reel them in and then shred them apart just to do it again and again. We cause pain, hurt, highs, extremely intense feelings and everything between. I don't set out to conquer it just happens!!! My ways are of me, not a plot to destroy or hurt unless I sense otherwise.
Long story short you may have NPD but it would have to be a PDOCs opinion not mine. As I have NPD and recognize it, so yes you can be and know it!!