Asking a doctor how many cells are in a human body is like asking an architect how much her buildings weigh.
How many cells?
I've no idea. Billions? Trillions?
It's either 106 or 109 cells in a cubic cm of breast tumour. You get a mutation every 106 breast cancer cells.
Figure it out yourself, Kevin. How many cubic centimetres are in you?
Clue: Who said, 'Eureka!' and why?
BTW I think there are about a trillion neurons (nerve cells) in a human brain.