We naturally don't derive energy from social interaction as much as being alone with our own thoughts. I personally like to have some social interaction but not on a daily basis. I think it is hard to find the right balance. I don't like to be completely isolated.
Article about Caring for your Introvert
http://en.wikipedia.org/wiki/Extraversion_and_introversion
Extroverts (also spelled extraverts[1]) tend to be gregarious, assertive, and interested in seeking out excitement. Introverts, in contrast, tend to be more reserved, less outgoing, but are also marked by a richer inner world. They are not necessarily loners but they tend to have smaller circles of friends and are less likely to thrive on making new social contacts. Introverts are less likely to seek stimulation from others because their own thoughts and imagination are stimulating enough.
The terms introversion and extroversion were first popularized by Carl Jung.[2] Virtually all comprehensive models of personality include these concepts. Examples include Jung's Analytical psychology, Eysenck's three-factor model, Cattell's 16 personality factors, the Big Five personality traits, the Four Temperaments, the Minnesota Multiphasic Personality Inventory, the Myers-Briggs Type Indicator, and Socionics.
Extroversion and introversion are generally understood as a single continuum. Thus, to be high on one is necessarily to be low on the other. While extreme introverts and extroverts are a psychological reality,[3][4] most people fluctuate between the two poles throughout their lives.
It is asserted that Americans live in an "extroverted society"[5] that rewards extrovert behavior and rejects introversion. "American culture values extroverted qualities more, and people often feel like they've been given the 'short end of the stick' after receiving their results on extroversion/introversion tests."[6]