Once upon a time, there was a female brain cell which, by mistake, happened to end up in a man's head. She looked around nervously, but it was all empty and quiet...
There were no other brain cells.

"Hello?" she cried...but no answer.

"Is there anyone here?" she cried a little louder, but still no answer....

Now the female brain cell started to feel alone and scared and yelled:

"HELLO, HEY, IS THERE ANYONE HERE?"

Then she heard a faint voice from far, far away say : " we're all down here...."