People (I'm looking in my phone's front-facing camera here. (Does anyone even know what a mirror is at this point in civilization? (How many parentheses can you nest before it becomes unreadable? (I'm guessing 4.)))) go through life with a filter. That filter often does a good job of protecting other's feelings, or maybe of keeping us from making a fool of ourselves. However, all too often it also does a masterful job of removing our sincerity, truthfulness, and the very soul of our emotion and reason. We filter ourselves out of our self. It's good to have wisdom in what we say and do, to let our experience and knowledge shape those things to be more effective, but not at the expense of being fake.
God didn't screw up when he made you and me. That part of you that you hate, that's a "thorn in your side", has a reason and shouldn't be covered up and ignored. Should it be controlled (if needed)? Absolutely, but a passionate person should never seek to kill his passion, or a quiet person strive to be loud. I would venture (in my completely unprofessional opinion) to say that trying to do so will eventually backfire anyway.
In conclusion (AAAHHHHHH!!!!! Senior essay flashbacks!), be yourself. If aspects of your personality need to mature or evolve, work on that, but don't cover them up and ignore that they're there. Sweeping stuff under the rug was never an acceptable way to clean up a mess anyways.