I'm an INTJ! Below are some general facts about INTJs, as well as observations that I think apply to me. Snagged from here.

• INTJ is the third rarest type in the population, and the rarest type among women (with ENTJ).
• Popular hobbies for the INTJ include reading, cultural events, taking classes, appreciating art, computers and video games, and independent sports such as swimming, backpacking, or running marathons.
• Famous INTJs include Hillary Clinton, Al Gore, Bill Gates, Dwight Eisenhower, Alan Greenspan, Ulysses S. Grant, Stephen Hawking, John Maynard Keynes, Ayn Rand, Isaac Asimov, Lewis Carroll, Cormac McCarthy, and Sir Isaac Newton.
• One of two types with highest college GPA
• Among types with highest income
• INTJs are comfortable with abstraction and theory but gain the most satisfaction from turning their ideas into reality.
• Often intellectual, they enjoy analysis and complex problem-solving, and are much less comfortable with the illogical and unpredictable nature of other people and their emotions.
• ... they are often perfectionists with extremely high standards of performance for themselves and others.
• The ideal job for a Mastermind allows them to use their analytical skills to problem-solve in a challenging environment, and to take responsibility for implementing their ideas to create efficient, innovative systems.
• INTJs' partners often find them difficult to read, and indeed they do not show emotion easily; they find the process of discussing emotions much too messy and disorganized. They enjoy solving difficult problems, but are often out of their depth when it comes to illogical, unpredictable personal issues.