Whose dream am I dreaming?

I was dreaming,
That I was a bird. 
I was a bird,
Flying higher and higher.
And I reached so high,
That I couldn't breathe any more.
I tried to turn back,
Back to the ground,
And suddenly the earth's gravity,
Pulled me hard;
I came crashing down!
I closed my eyes with my wings, 
And woke up with a jolt,
I had my hands on my eyes,
And I was crying.
I cried so much,
The my tears flooded the room.
I opened the room,
And ran out,
But my tears flooded the whole place;
I started drowning in my own tears,
I could hardly breathe!
I tried hard to swim to the top,
There was no stopping,
The only way was to fly off,
From this flood of tears.
I flapped my hands,
With all my might,
But the tears entered me,
And filled in my lungs.
I woke up with a shock,
Flapping my fins,
As hard as I could.

Alas, I don't know,
Whom am I,
A bird, a man or a fish?
Or is this all a dream? 

Whose dream am I dreaming?