First impressions

I don't need to tell everyone that first impressions are very important, not just during work but also your social life. When someone give others a bad first impression, they'll find it hard to climb back up to gain someone's liking. I see a few "friends" of mine having this kinda problem and i myself also face this. 
I'm usually shy and it usually takes sometime before i can be comfortable around to talk normally with others. So on first meeting, i give people the impression that I'm quiet and shy sometimes even serious and bored. It took me some time and effort to change their perspective as they will finally see who i really was when i interacted more with them. I still the same challenge even now.
My "friend", well, my first impression of her was she's rather uh.. pushy. She's gives the vibe of a demanding spoilt brat. She swore on the first day we met (not at me) That's her huge mistake. I don't like people who swears for nothing and she just manage to earn that ticket down loser ville from me. I lost almost all respect for her and the reason i still talk to her today was cuz I'm being kind. After some time she redeemed herself a little but mostly i still do avoid her. You can sense when you don't get along well with some people.
And may i mention, I have an acquaintance who met a girl that told her about her first sex experience on the first day they met. That's a HUGE no no. As much as people like being nosy about others personal life, there's a limit to how much info you can reveal to a person you just met. Something like that is definitely unnecessary and it just gives people the impression that you don't keep secrets well and you're defenceless. To show them your weaknesses on the first day itself? Usually it ends bad, i'd say~~
But then, I'm not telling you to be a hypocrite or act too out of your personal principle. People will eventually grow to hate you once they see the real you. Just be yourself and let them decide if they want to hang out with you. For what's worth, it's much better than having to face a fight in the future.