It's funny; my personality would appear to be almost the exact opposite of yours, Alex. I have this deep conviction that I should not share every single aspect of my life with people. This stems from two main reasons: paranoia and a lack of faith in the excitement of my life.
I'm perpetually paranoid that anytime I tell a story regarding a particular person, that person will be standing right behind me. It's not even that I'm making some disparaging remark; I just don't like people talking about me behind my back so I guess I don't feel comfortable doing the same to other people? I try not to gossip a lot, although I feel like I've been slipping into the habit more and more frequently as of late. Sometimes it's just so difficult. Plus, what else is there to talk about? Virtually every conversation is some form of gossip, even if it's not malicious.
Alternatively, sometimes I'm about to say something (or I'm halfway through a sentence) and then I think, "Eh, nobody really cares." It creates awkward silences sometimes, but what can you do? I am of great importance to myself. I am probably of less importance to other people. I feel the need to cap the flow of Endless Things that I Say.
Or there are times that I get so frustrated with people's conversations that I just have nothing to say. I get that not every one of your conversations has to be intelligent, but some things seem so insignificant. Don't get me wrong, I frequently discuss the most pointless and mundane things, but I don't see the point in talking about How Quickly He Replied to your Message on Facebook or If Her Use of a Smiley Face was Sincere or an Accident.
The OTHER other reason is that I don't like drama. (Although I do love Drama.) Ever since I was in elementary school, I've distanced myself from conflicts. I guess it's both a good and a bad trait (Good: not a bitch.* Bad: SO not assertive). I love teenagers, even when we're insufferable, and there are many positive sides of having a lively group of friends. HOWEVER, that should not translate into a need to make a huge deal out of every single thing on Earth. (Similarly, perhaps your life would be a good deal less dramatic if you could stop talking about people behind their backs! Honestly!) Again, perhaps it's just because I'm not assertive, but I am quite good at Chilling the Fuck Out when it comes to STUPID STUPID ARGUMENTS. (I'm not as good at it when it comes to happy excitement or things I really care about.)
Unfortunately, the first "ingrained" trait that pops into my head is my tendency to interrupt people. It's terrible; I hate when people interrupt me. I can't stop the words! They take over my life! ** Also, I feel like I talk about myself too much. I don't know other people view me - maybe it's just how human nature is - but it's like I have a story relating to myself for every occasion. I happen to believe that people are inherently narcissistic, though, so maybe I'm just a pessimist. ***
* Well, I suppose that's subjective...
** Additionally, I hate that moment when the other person pauses and you think they're done so you start talking and then you end up accidentally interrupting them.
*** This probably seems to conflict with the previous paragraphs, so: the stories I DO tell are usually either about people who don't the person I'm talking to, or are things that happened a long time ago and therefore do not have an impact on anyone's life. Or they're all about ME. (whoooooooo)