Do you know your Myer's-Briggs Personality Type? If not, you can take a free test here (try not to choose the middle answer) - http://similarminds.com/jung.html

I know most of my friends' personality types and I find most of the descriptions pretty accurate! I can also "guess" people's personality types after a few interactions and get it right most of the time.

I/E = introvert or extrovert
N/S = intuitive or sensing
F/T = feelings-oriented or thinker-oriented
J/P = judging (more planner oriented) or perceiving (more spontaneous/go with the flow)

I'm an INFJ/ISFJ