'Who am I?' (self-confusion)

I smile to you, with such energy.
Make a joke.
Laugh.
Pat your shoulder, comfort you.

I'm home. Looking at myself in mirror.
Are those feelings even true?

Next day. I'm quiet. I don't care.
I avoid them. Only cold stare.

Where did all emotions go? Thinking. Still, I wouldn't know.

Other day. I'm rude. Selfishness is to show.
Why? Don't understand.. Just let it go.

Following day. Confidence. What am I so confident about?
Either way, I feel proud.
So through city I walk around,
not paying attention on the crowd.

To home I return. Sit on the bed. Again looking at the mirror,
at eyes reminding dead.
The mind is blank, like there was nothing in my head.

Yet I think of passed days. Trying to figure out myself.

What is real? What is true? And how'd I knew?
If everything is a lie..
Then the question stays..

Who am I?