Ramblings: Extroverts vs. Introverts

So, as I mentioned in "Ramblings: Who really has the power over school social status?", I am, fundamentally, an introvert. Many people in my life since starting university might think me to be an extrovert - I always seem to be doing more things with more people than I can actually fit into any given space of time, I seem to speak reasonably easily to other people, and I love a good party. But really, I'm not an extrovert.
For every night I spend out with others, I spend one inside, not being able to face another night out with people. Most of the time, when a big night out is planned, I would much rather just have a chat over a pint at the local pub. I would generally rather kick back and watch a movie with my flatmate, or write some poetry, than head out to a nightclub. Being out with lots of people, all the time is, to put it plainly, hard for me.
That is not to say that I dislike social situations. In fact, I like people, and I like being around people, but it can be exhausting. And it is not to say that I don't like parties. In fact, I love a good party, if even a group of the people are familiar, and faces are friendly. Eventually, I'll even venture into the nightclub scene if I've already had enough of the party to get me fired up for the night. But whether I have been drinking or not, Iseem to find myself huddling away somewhere in an effort to get away from the exhausting effect of just people.
Over the last term, I have found myself moving slightly away from the regular drinking of the OTC-ers in a bid to more easily recharge myself in time for uni, and even at weekends away, I rarely spend more than £5 at the bar unless there is a big do on (such as the big dinners). Then I find myself going all out in true night-out extroverted-type-fashion.
The thing is, being introverted isn't about being shy, or even hating social situations, its about the exhausting effect that people can have on you if you are around them too long. Sure, shyness, or hatred can appear the cause, but more often than not, is just the effect of the difficulty from being around people too much. I believe at one point that there was some research done on the differences in brain pathways between introverts and extroverts. I can't remember the exact details, but it concluded that the thoughts of introverts involving the external world followed a less direct pathway than those of extroverts, potentially producing more internal thought, and also, their sensitivity to the brain-chemical dopamine. Extroverts are apparently less sensitive to this chemical, and so need plenty external-input to produce adrenaline to keep them happy, but introverts are more sensitive to the hormone, and so too much external sensory input overwhelms them, meaning they often prefer to keep out of very social situations or large crowds.
In my case, the thing that keeps me sane, is balancing my social life and my quiet time. Too much quiet time, and I can feel lonely and depressed, but too much social time and I get tired and depressed. Somewhere in the middle is a happy medium, and I'm a better, saner person to be around then.