A state of mind

When a person says, Hey I'm happy. Is that a state of mind? Just how do we define happy or unhappy?
I may be a good example since I'm so neutral in my external persona that although I may emit unhappy signals, internally, it's just the opposite. Remember times in playschool when teachers tell kids, "show me a happy face!" - the kids will then smile and laugh. If it was "show me a sad face" - the kids would frown and pretend to cry. Apply that idea and the concept will come through clearly.
We may be unhappy with the general state of things, but it doesn't have to mean that we are unhappy with our lives. It's 2 different things.
For a start, the general state of things may not be in our direct control - there are other factors to take into consideration. Our lives are a different thing. It IS in our direct control and although there are a few splinters here and there, we are capable of still being happy with it.
That's why, happiness or unhappiness IS a state of mind.
We choose to float at the level we wish to, at that moment.
Because of that, it's not necessarily the actual state of mind.
Perhaps that's why I'm an introvert - I'd rather just let myself know my state of mind. For me, that state belongs to me - and sometimes, sharing that is just too precious.
Next time someone says - I'm unhappy and they are almost as complicated a person as I am, think again.
It's never just that.
It's always something else.