Update

For me, it really depends. Some people are really faking it in my point of view. You just cant talking behind ppl back and being nice to him or her after that right? 

                                                     

Its the truth though. I do realised sometimes I did something I said I am never going to do it or say it. 

From my observations, it also happened to people around me. which I found it kind of kena betrayed. 

Many times.