Let me preface this discussion by saying that it is purely and observation-based opinion (OBO), but as with all opinions some will find it useless. I'm also certain that others can improve upon it, and I invite anyone to disagree with me and suggest other things. And finally, I in no way claim that this will hold true for every person, but certain people that would like to match their personality with their profession may find this helpful or, at the least, thought-provoking.
The monk style of play requires good management, awareness, strategy, and planning. Things that hurt the monk are aggression, mano-a-mano, and an inability to focus on multiple things at once. The monk is one of the most mental professions. I am not a very physical person, but I love to strategize and "flex" my brain. I started noticing that the things that make a good monk match who I am. My second favorite profession? MM necro, which require a very similar style of play.
Here are some thoughts on some of the other professions or builds:
Warrior:
Pros - aggression, determination, confidence, big sibling mentality
Cons - timidity, over-thinking, a love of mending
Elementalist (Nuker):
Pros - aggression, management, mind-over-matter
Cons - Army of one mentality, toughness, ego
Interrupter (Ranger or mesmer):
Pros - awareness, agility (got to get those clicks in fast), management
Cons - aggression, impatience
Assassin:
Pros - quick-thinking, "cowardice" (disable, get away, let the others finish), agility
Cons - over-confidence, arrogance, aggression, ownership
Paragon:
Pros - leadership, team player, selflessness
Cons - individualism, anti-social disorder
Dervish:
Pros - self-reliance, passive-aggression
Cons - dependency
Ranger (trapper):
Pros - wit, passive-aggression, sadism
Cons - impatience
Feel free to add on or suggest alternatives. I haven't done ritualist, necro, or other builds. What is your story on how your personality affects your preferred profession/build? Have fun
