My theory on the pyramids...
One day a Pharaoh was sitting around bored. This Pharaoh was a big jokester. One day he was looking out side and thought "What if I built a giant stone building for no purpose! Then everyone would be sitting around all day trying to figure out the purpose!". And so he had one built. And those who took his place later looked at his work and thought "Well I can't have people questioning why he built one and I didn't!" and so more were built. And thus the biggest practical joke in the history of humanity (I mean besides the whole "apple thing") happened.
And thousands of years later and we still fall for it and the mummy of that great Pharaoh laughs...or atleast he would if mummies could laugh...can mummies laugh? Doesn't seem like those bandages were designed for movement. Doubt the jaw would work all that well after mummification either. I doubt they can laugh. Probably a double practical joke then, poor Pharaoh who wants to laugh at all the silly people he tricked but his people tricked him by mummifying him so he can't laugh. Those Egyptians are known for being big jokers.