Fake?

I was recently accused of being this by someone I consider to be a good friend. I usually don't let comments like this bother me, and I don't even know why I let it bother me this time as he seems to be the only person that I know so far that thinks of me this way. I am myself as much as I can possibly stand it and its hard for me to hide anything from people (although I admit that on rare occasions I try). Hearing this makes me unsure of myself as a person being told that I'm "overly happy all the time". I bet he wouldn't think that if he knew me as well as he thinks he does.

So what exactly makes a person seem fake? Can a person put on an act and try to hide themselves without even realizing it?

I have no sources on this except for my own thoughts and feelings as I haven't found anything besides tips for thespians so far. Thoughts and opinions from others are appreciated.

To me, being "fake" does not mean always being in a good mood. It could be that things are going well every single day of that persons life, who knows? A person could pretend to act a certain way to get whatever it is they want. Although, maybe thier chipper tone of voice and that smile plastered to their face really is genuine (or maybe they're just stuck that way, I don't know)? Do we just hate people that never seem to have a bad day? If so, then I don't know what to think, because I certainly haven't met anybody who never has a bad day.

On the other hand, what if they constantly try to hide the bad things going on? Does that make them fake? Are they being fake when things go bad at home and are threatened into hiding it from the rest of the world? Are they fake if they're embarrassed to admit they're not perfect? What if they're insecure or upset? Is it a bad thing to try and hide those feelings (in my mind, obvious answers say yes)? What if people put a mask on for a really big reason?

I'm surprised that I have so many questions. I normally don't have any...