Does someone you know(or you yourself) manipulate and tailor their personality around other people?

Okay, so of course the way I talk to my parents is going to be a different than the register I use to talk to my friends – but doesn’t it irritate you when someone you know (a friend or person in close relations) completely changes in front of other people? Maybe I could see acting a little differently in front of certain people or not quite acting yourself until you adequately get to know someone, but I feel like there is a certain set of character, mannerism, morality and ethical sense that should always be consistently identifiable in a person.

It’s happened a few times when people I know completely switch characters and transform into a different person, as if to “show off” or demonstrate what a different person or crowd wants to see. It irritates me! Why can’t people just be themselves?