I would say that the problem with D&D-style alignments is their excessive static nature. But in reality, things are not so... For example, I was a fan of evil forces until I was 16 and considered egoism the only correct norm of behavior, and now I definitely define myself as good and altruistic:...
It doesn't matter who you think you are. What matters is who you are. Besides, many people "play villains" until they are 16. You might have considered yourself a Satanist, but in reality, you wouldn't hurt a fly.
As for me, I consider myself True Neutral :D