To be or not to be!

Character the most important thing for a person.He gets judged based on that,he makes friends based on that n enemies too..it can take you to greater heights or pull you down deep.I was just wondering if one should be themselves n not care about what others think of it (I guess thats what means "Be Yourself")or tweek it in such a way according to the situation or according to the people around you.Say i am a quiet person by nature and not extrovert....does that mean i be myself n dont care a shit as to what people think of me or should i take that extra effort n take steps to talk to people so that people dont think that i am a boring person.Everyone who is reading this would definitely say option 2.That was just a simple one now say i hate a person but he would be the only person who could help me so do i just turn the plate around and be nice to him till the work gets done ok!now this is management according to few and being fake according to the others.One could face many such situations in a day but people who turn around are the most succesfull people.And those whose do i always wonder how they do that so smartly because every time i tried i am just half way through the effort i feel why the hell am i doing this i am not this person i should not try not to be me!!such confusing shit@#$%.I dont want to strain myself any more shall leave it here n see if i have any comments or advice on this.