Interesting how some have said they're different in different environments. I'm the same in all situations. Obviously, there are places where I don't go on about my opinion, but I always express it, even if it isn't popular. I've stood up to work place bullies on behalf of others, even when it turned the bullying on me. Actually, I've done this several times. Twice, recently.
I'm not overtly rude to those I dislike, but I will stop contact with them, and if at work, minimise it as much as possible.
Maybe that is why I make friends so easily. I stand up for the underdog and I'm not two-faced. I'm also very kind and supportive, BUT if someone abuses that, they don't get a 2nd chance. And many people try to.
It's that old saying, isn't it? Don't mistake my niceness for weakness.