Why are you the way you are?

This is a little long but the question was on my mind...

So I've been reading all these cases and articles trying to explain why certain industries are consolidated, or why certain cultures work most in building a high performance business.  And I've read Outliers by Gladwell recently which attempts to answer why talented businesspeople, hockey players, and lawyers became who they are.  The short answer being luck, timing, and a support network which propagated intelligent repetition.

But beyond talent, have you ever wondered why you are the way you are?  What makes you angry, sad, happy, messy, grumpy, laugh?  What makes you like or love a certain person, but hate another?  What makes you react one way in a given situation, and another with only a minor difference in context?  We know the broad, generalized answer is a mixture of genetics and environment (the whole nature / nurture construct), but what specifically in nature / nurture made you the way you are?  

For example, I'm a messy person - my worktable is filled with strewn papers, chewing gum packs (orbitz if you have to know), and business cards.  I almost never put my coats back on the hangar - I always leave them on the couch or a chair.  I inevitably clean all this stuff up, but I've never learned how to be organized in a continuous process.  I think I'm like this because my home was pretty messy growing up (our home was never clean) as our family business demanded so much time and effort, and I was never punished for disorganization.  Also, it reflects my thinking - I tend to be nonlinear at times and my imagination hops around like a rabbit on crack.  Similarly, my sister's home is pretty messy, though we both clean up when guests come over.  Whenever I see someone's clean, organized desk, I'm always a little envious - and completely baffled on how he/she does it.

Now it's impossible to explain a person entirely (or is it?), but of the few most prominent features of what defines you, how would you explain those features?  If you dig enough, there's an interesting story behind the little tics and characteristics which explain who are better than broad philosophical statements like "loyalty" or "hard work." Certainly, the answers won't be consistent

PS  on a more ironic note, I wonder if I can explain why I send out these random question emails.  Some of the reason is pretentious - I mean, I think understanding who we are helps us get some meaning or truth out of life.  

Some of it is just distraction - all my coursework is so analytical and causative, that it fails to take into account the complex, nonlinear, and unpredictable aspects of existence.  Life is boring if all we do is plug a formula, interpret data / facts, and make obvious assertions.  

And some of it is just curiosity - so much of what we know about each other are these small snippets of shared experiences which do little to truly reveal who we are, because the tricky part is that you can't ask this question directly.  It's like staring into the sun - you only get a true sense of its heat and light by feeling it, or seeing the reflection, never by staring directly into it.