I think there is two reasons that has influenced my choice to use a pseudonym. One is psychological: I am a person that like to keep at least part of my life closed to people outside of my nearest family and often even to them too, with my wife as the only exception. The second has something to do with my career, my view of art and my weariness with social communities in general.

Creating a pseudonym was satisfying in many ways - career-wise because I was able to start all over (career originally meaning a road or a course is demonstrating it quite well - taking a new road), artistically because I could start working in a new category without having to bridge back to my previous works and also because I could move from so called Fine Art to the more humble genres that I view as just as valid artistically. The last has also to do with my weariness with the art world and its boring audience.

All this made a fine harmony with my personality - and a last benefit was that I, like @meesterboom mentions, could invent a new and mysterious name.